Biosensors

18 pages, 2478 KB

Open AccessArticle

Rapid Detection of Fumonisin B1 Using a Fluorescent Aptasensor with Plasmon-Modified Graphene Oxide as a Quencher

by Yi Jiao, Xiaoqing Yang, Junping Hao, Yuhang Wen, Shanshan Wang, Jingbo Zhang, Hengchao E, Zhiyong Zhao, Jianhua Wang and Xianli Yang

Biosensors 2026, 16(2), 133; https://doi.org/10.3390/bios16020133 - 22 Feb 2026

Viewed by 168

Abstract

Fumonisin B1 (FB1) is a secondary metabolite produced by Fusarium species, exhibiting strong toxicity and classified as a Group 2B carcinogen by the International Agency for Research on Cancer. It poses a significant threat to both human and animal health. Therefore, developing a [...] Read more.

Fumonisin B1 (FB1) is a secondary metabolite produced by Fusarium species, exhibiting strong toxicity and classified as a Group 2B carcinogen by the International Agency for Research on Cancer. It poses a significant threat to both human and animal health. Therefore, developing a simple and reliable method for FB1 detection and analysis is imperative. In this study, a biosensor based on nucleic acid aptamers was developed, utilizing plasma-modified graphene oxide (mGO) as a fluorescence quencher for FB1 detection. This system leverages the interaction between mGO and FAM-APT (a nucleic acid aptamer labeled with 5-carboxyfluorescein, FAM), achieving fluorescence quenching through fluorescence resonance energy transfer (FRET) under excitation at 490 nm and emission at 520 nm. In the presence of FB1, FAM-APT specifically binds to FB1 and dissociates from the mGO surface, resulting in fluorescence recovery. Quantitative detection of FB1 was achieved by measuring the differential fluorescence intensity. The biosensor demonstrated excellent linearity over a concentration range of 10 to 5 × 10⁶ ng/L, with a detection limit (LOD) as low as 0.16 μg/L. Additionally, the sensor exhibited high specificity for FB1 among six common mycotoxins. In practical sample analysis, recovery rates ranged from 95.8% to 104.7% in corn samples and from 89.3% to 94.5% in rice samples. This aptamer-based biosensor features a simple structure, high sensitivity, and a wide detection range, providing important technical support for advancing mycotoxin research. Full article

(This article belongs to the Special Issue Advanced Biosensors Based on Molecular Recognition)

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13 pages, 2502 KB

Open AccessArticle

A Nanobody-Based Lateral Flow Assay for Point-of-Care Diagnostics

by Timothy A. Bates, Sintayehu K. Gurmessa, Jules B. Reyes-Weinstein, Eric Barklis and Fikadu G. Tafesse

Biosensors 2026, 16(2), 132; https://doi.org/10.3390/bios16020132 - 22 Feb 2026

Viewed by 92

Abstract

Lateral flow assays (LFAs) are among the most successful technologies for point-of-care and at-home testing, but further advances are needed to reduce costs and accelerate development. Alpaca-derived nanobodies (Nbs), single-domain antibody fragments, are promising immunoassay reagents across diverse applications. Their small size and [...] Read more.

Lateral flow assays (LFAs) are among the most successful technologies for point-of-care and at-home testing, but further advances are needed to reduce costs and accelerate development. Alpaca-derived nanobodies (Nbs), single-domain antibody fragments, are promising immunoassay reagents across diverse applications. Their small size and ease of recombinant production make them particularly well suited for diagnostics. Here, we present a paper-based LFA targeting the SARS-CoV-2 nucleocapsid (N) protein that exclusively uses Nbs for direct antigen detection. We also demonstrate in-house synthesis of Nb-coated gold nanoparticles, enabling instrument-free visual readout and detection of N protein down to 40 ng/mL. This design avoids components that require mammalian cell culture and can be produced entirely from in-house reagents, simplifying manufacturing and lowering component costs. Because the assay is read visually without an external reader, it is well suited for deployment in resource-limited settings. Together, these results highlight the speed and practicality of developing Nb-based LFAs and suggest a broadly applicable strategy for detecting other clinically important disease biomarkers. Full article

(This article belongs to the Special Issue Biosensing for Point-of-Care Diagnostics—2nd Edition)

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88 pages, 10299 KB

Open AccessReview

Fungal Frontiers in (Bio)sensing

by Gerardo Grasso

Biosensors 2026, 16(2), 131; https://doi.org/10.3390/bios16020131 - 22 Feb 2026

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Abstract

Filamentous fungi are increasingly recognized as versatile biological platforms for the development of advanced (bio)sensing technologies, owing to their extensive secretory capacity, material-forming ability, and intrinsic bioelectrical activity. This review critically surveys recent progress in fungal-based sensing within a multiscale framework spanning molecular, [...] Read more.

Filamentous fungi are increasingly recognized as versatile biological platforms for the development of advanced (bio)sensing technologies, owing to their extensive secretory capacity, material-forming ability, and intrinsic bioelectrical activity. This review critically surveys recent progress in fungal-based sensing within a multiscale framework spanning molecular, material, computational, and ecological domains, with particular emphasis on developments reported over the past five years. Key advances involving secretome-derived biomolecules, mycogenic nanomaterials, mycelium-based living materials, and fungal electrophysiology are discussed alongside emerging approaches for environmental monitoring that integrate sensor networks, imaging platforms, and data-driven analytics. Collectively, these works demonstrate that fungal systems can enhance biosensor sensitivity, selectivity, and sustainability, while enabling unconventional paradigms of signal transduction, material-integrated sensing, and biologically mediated computation. At larger spatial and temporal scales, mycelial growth dynamics and electrical activity provide measurable responses to mechanical, chemical, and environmental perturbations, supporting early applications in wearable devices, structural materials, and ecosystem monitoring. Despite significant progress, challenges remain in reproducibility, long-term stability, mechanistic understanding, and scalable device integration. Overall, the evidence reviewed highlights filamentous fungi as biologically adaptive and ecologically embedded systems with substantial potential to support next-generation (bio)sensing technologies, while underscoring the need for integrative approaches that combine biological insight with materials science, electronics, and artificial intelligence. Full article

(This article belongs to the Special Issue Nanotechnology Biosensing in Bioanalysis and Beyond)

20 pages, 2478 KB

Open AccessArticle

Practical Considerations for Continuous Monitoring of Hexavalent Chromium in Wastewater Using a Microbial Fuel Cell Biosensor: Biosensor Fabrication, Sample Pretreatment, and Bacterial Community Analysis

by Guey-Horng Wang, Chiu-Yu Cheng and Ying-Chien Chung

Biosensors 2026, 16(2), 130; https://doi.org/10.3390/bios16020130 - 21 Feb 2026

Viewed by 85

Abstract

Hexavalent chromium (Cr(VI)) is a high-priority environmental pollutant due to its strong oxidizing properties, which cause DNA damage and other severe health effects. Conventional detection methods are often costly and lack real-time monitoring capabilities, creating a strong demand for cost-effective, real-time biosensors that [...] Read more.

Hexavalent chromium (Cr(VI)) is a high-priority environmental pollutant due to its strong oxidizing properties, which cause DNA damage and other severe health effects. Conventional detection methods are often costly and lack real-time monitoring capabilities, creating a strong demand for cost-effective, real-time biosensors that meet industrial requirements. In this study, we developed a novel biosensor for continuous Cr(VI) monitoring using a single-chamber microbial fuel cell (MFC). The biological element is an engineered Escherichia coli strain (ChrA-ChrB-E. coli), constructed by introducing Cr(VI)-resistant (ChrA) and Cr(VI)-reducing (ChrB) genes. The presence of Cr(VI) affects bacterial metabolism and electron transfer within the MFC, generating a measurable signal proportional to the contaminant’s concentration. The biosensor demonstrated robust performance and characteristics. The recombinant strain retained functional activity after 450 days of storage at −20 °C. The system exhibited high sensitivity and excellent linearity (R² ≥ 0.999) across a broad Cr(VI) concentration range of 0.015–200 mg/L. During continuous monitoring of chrome tanning and electroplating wastewater, measurements deviated by less than 2.33% from the standard diphenylcarbazide (DPC) method; electroplating deviation was further reduced to −0.69% with EDTA pretreatment. In fishery water, the deviation was higher (−7.12%) due to dissolved oxygen (DO) interference but was reduced to −0.75% after mechanical stirring to remove DO. The biofilm bacterial community remained highly stable over six months in both wastewater types, with the inoculated ChrA-ChrB-E. coli strain maintaining dominance (>99.6%). These results substantiate the feasibility of using this biosensor for continuous, online, real-time detection of Cr(VI) in actual wastewater environments. Full article

(This article belongs to the Special Issue Environmental and Agricultural Biosensors)

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16 pages, 2735 KB

Open AccessArticle

Multiplexed Detection of Cancer Biomarker Using a Dual-Mode Colorimetric-SERS Lateral Flow Immunoassay Based on Elongated Rod Ag Nanoshell (ERNS) SERS Tags

by Sungwoo Park, Yeonghee Jeong, Sohyeon Jang, Cho-Hee Yang, Jun-Sik Chu, Homan Kang, Seung-min Park, Hyejin Chang and Bong-Hyun Jun

Biosensors 2026, 16(2), 129; https://doi.org/10.3390/bios16020129 - 21 Feb 2026

Viewed by 101

Abstract

Early detection of cancer biomarkers in blood is critical for improving patient outcomes; however, conventional immunoassays often rely on complex instrumentation and are not well suited for point-of-care testing or multiplexed analysis. Herein, we present a dual-mode colorimetric–surface-enhanced Raman scattering (SERS) lateral flow [...] Read more.

Early detection of cancer biomarkers in blood is critical for improving patient outcomes; however, conventional immunoassays often rely on complex instrumentation and are not well suited for point-of-care testing or multiplexed analysis. Herein, we present a dual-mode colorimetric–surface-enhanced Raman scattering (SERS) lateral flow immunoassay (LFIA) platform for multiplexed detection of cancer biomarkers, employing elongated rod-shaped silver nanoshells (ERNSs) as SERS nanotags. The ERNS features a rough Ag shell with internally incorporated Raman labeling compounds (RLCs), enabling plasmonic extinction for visual readout and strong SERS signals for quantitative analysis while preserving the external metal surfaces for efficient antibody conjugation. Leveraging these advantages, a multiplex LFIA capable of simultaneously detecting prostate-specific antigen (PSA) and carbohydrate antigen 19-9 (CA19-9) on a single strip was successfully demonstrated. Visual inspection enabled rapid discrimination of samples at or near clinically relevant cut-off levels, while Raman analysis achieved limits of detection of 8.0 × 10⁻³ ng/mL for PSA and 5.4 × 10⁻² U/mL for CA19-9, corresponding to approximately 500-fold and 685-fold lower concentrations than their respective clinical thresholds. This ERNS-based colorimetric–SERS LFIA integrates rapid screening and highly sensitive quantification within a single platform and offers a versatile nanoprobe design strategy for multiplex biomarker detection and liquid biopsy-based diagnostic applications, with potential relevance to point-of-care settings. Full article

(This article belongs to the Special Issue Surface-Enhanced Raman Scattering in Biosensing Applications)

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14 pages, 1814 KB

Open AccessArticle

Development of a Gold Nanoparticle-Based Amplification-Free Nanobiosensor for Rapid DNA Detection Supported by Machine Learning

by Yunus Aslan, Yeşim Taşkın Korucu, Brad Day and Remziye Yılmaz

Biosensors 2026, 16(2), 128; https://doi.org/10.3390/bios16020128 - 20 Feb 2026

Viewed by 198

Abstract

The global expansion of genetically modified (GM) crop cultivation has increased the demand for analytical platforms that can provide rapid, reliable, and cost-effective detection of GM-derived ingredients to support traceability, regulatory compliance, and accurate labeling. Conventional molecular assays such as polymerase chain reaction [...] Read more.

The global expansion of genetically modified (GM) crop cultivation has increased the demand for analytical platforms that can provide rapid, reliable, and cost-effective detection of GM-derived ingredients to support traceability, regulatory compliance, and accurate labeling. Conventional molecular assays such as polymerase chain reaction (PCR) and isothermal amplification are highly sensitive and specific but depend on sophisticated instrumentation and trained personnel, limiting their applicability in field settings. Here, we present a label-free and amplification-free nanobiosensor based on citrate-capped gold nanoparticles (AuNPs) for the direct colorimetric detection of the Cry1Ac gene associated with the MON87701 soybean event, without the use of polymerase chain reaction (PCR) or any enzymatic nucleic acid amplification step. The assay relies on the localized surface plasmon resonance (LSPR) of AuNPs, which induces a red-to-purple color transition upon hybridization between complementary DNA strands. Critical reaction parameters, including NaCl concentration, AuNP size, and ionic strength, were optimized to enable selective and reproducible aggregation. Integration with a Support Vector Machine (SVM) algorithm enabled automated spectral classification and semi-quantitative discrimination of GM content levels. The optimized AuNP–SVM system achieved high sensitivity (limit of detection ≈ 2.5 ng μL⁻¹, depending on nanoparticle batch), strong specificity toward Cry1Ac-positive sequences, and reproducible classification accuracies exceeding 90%. By eliminating enzymatic amplification steps, the proposed platform significantly reduces assay time, operational complexity, and instrumentation requirements, making it suitable for rapid on-site GMO screening. Full article

(This article belongs to the Special Issue Advanced Biosensors Based on Molecular Recognition)

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11 pages, 578 KB

Open AccessArticle

Investigating Roles of Cerebral Blood Flow to Maintain Thermal Stability of Neonatal Brain Against Cold Stress Using Non-Invasive Probes for Brain Perfusion and Temperature Gradient

by Sachiko Iwata, Kennosuke Tsuda, Masahiro Kinoshita, Shinji Saitoh and Osuke Iwata

Biosensors 2026, 16(2), 127; https://doi.org/10.3390/bios16020127 - 20 Feb 2026

Viewed by 127

Abstract

Background: Brain temperature is an important determinant of neurological outcomes in ill infants, yet contributions of environmental temperature and cerebral blood flow remain uncovered because of the lack of non-invasive probes. Methods: Using non-invasive cot-side probes, we examined how cerebral blood flow influences [...] Read more.

Background: Brain temperature is an important determinant of neurological outcomes in ill infants, yet contributions of environmental temperature and cerebral blood flow remain uncovered because of the lack of non-invasive probes. Methods: Using non-invasive cot-side probes, we examined how cerebral blood flow influences brain temperature during mild cold stress induced by incubator-to-cot transfer. We studied 43 clinically stable infants in a tertiary neonatal intensive care unit. After cot transfer, infants were routinely fitted with knit caps and wrapped in cotton blankets. Scalp and superficial and deep brain temperatures were measured using infrared and zero-heat-flux thermometers, and superior vena cava (SVC) flow—a proxy for cerebral blood flow—was assessed using Doppler velocimetry before, immediately after, and 2 h after transfer, adjusting for rectal temperature. Results: Ambient temperature decreased from 29.7 (SD 0.8) °C to 26.8 (SD 0.9) °C, while rectal temperature remained stable. Scalp and brain temperatures declined after transfer but superficial and deep brain temperatures returned to baseline after 2 h of cap use. The regression coefficient between SVC flow and superficial brain temperature shifted from −0.176 (95% CI, −0.386 to 0.035) to 0.239 (−0.280 to 0.759) after transfer (difference: 0.415 [0.106 to 0.724]; p = 0.009), and then returned to baseline after 2 h (−0.079 [−0.528 to 0.372]). Conclusions: Relationships between brain temperature and perfusion were successfully monitored using non-invasive cot-side biosensors; cerebral blood flow appears to shift from facilitating heat dissipation in warm conditions to supporting heat delivery during cold stress. These findings underscore the physiological role of cerebral blood flow in maintaining brain temperature. Full article

(This article belongs to the Special Issue Advanced Biosensors for Disease Screening, Monitoring, Diagnosis, and Treatment—2nd Edition)

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22 pages, 4421 KB

Open AccessArticle

Integrated Microfluidic Chip Enabling Preparation and Immobilization of Cell-Laden Microspheres, and Microsphere-Based Cell Culture and Analysis

by Qiongyao Mou, Peiyi Zhang, Daijing Li, Qiong Wang and Jun Yang

Biosensors 2026, 16(2), 126; https://doi.org/10.3390/bios16020126 - 19 Feb 2026

Viewed by 126

Abstract

Microfluidics-based preparation methods for cell-laden hydrogel microspheres are well-suited for large-scale comparative analysis of single or few cells. However, in existing studies, the preparation of cell-laden hydrogel microspheres and the cell culture process are typically separated, requiring the fabricated microspheres to be eluted [...] Read more.

Microfluidics-based preparation methods for cell-laden hydrogel microspheres are well-suited for large-scale comparative analysis of single or few cells. However, in existing studies, the preparation of cell-laden hydrogel microspheres and the cell culture process are typically separated, requiring the fabricated microspheres to be eluted and transferred from the preparation device to cell culture dishes or plates for cultivation. This transfer process can easily compromise sterility, while conventional cell culture methods consume more reagents and cause microsphere stacking, hindering single-cell observation and analysis. To address these issues, this paper presents an integrated microfluidic chip that sequentially enables droplet generation with cell encapsulation, gel droplet solidification, hydrogel microsphere trapping, and microsphere-based cell culture and analysis, facilitating the cultivation and observation of single or small numbers of cells. Integrating cell-laden microsphere preparation and 3D cell culture within a sealed chip structure reduces contamination risks associated with cell transfer, enables automation of multiple cell analysis workflows, and minimizes reagent and sample consumption. Using polydimethylsiloxane (PDMS) with good gas permeability and processability as the chip material, biocompatible fluorinated oil was selected as the oil phase for microsphere preparation. A mild sodium alginate-calcium ion gelation system was employed, where calcium ions were released under acidic conditions after droplet generation to trigger solidification, yielding uniform hydrogel microspheres. Under optimized conditions, the single-cell encapsulation efficiency for test samples of human myeloid leukemia cells (K562) was 33.8% ± 1.8%, with a size uniformity coefficient of variation (CV) reaching 3.85%. Cells encapsulated within hydrogel microspheres were cultured in 286 on-chip independent cell culture chambers, achieving >95% viability after 24 h. Full article

(This article belongs to the Special Issue Advanced Cell-Analyzing Technologies and Their Biosensing Applications)

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8 pages, 5402 KB

Open AccessCommunication

A Suspended Graphene Field-Effect Transistor for Ultra-Sensitive and Label-Free Detection of Cancer Biomarker miR-21

by Zhiming Deng, Cong Zeng, Qihang Wu, Fumin Zhang and Pingping Zhuang

Biosensors 2026, 16(2), 125; https://doi.org/10.3390/bios16020125 - 18 Feb 2026

Viewed by 189

Abstract

The sensitive detection of microRNA-21 (miR-21), a key biomarker for various cancers, is crucial for early diagnosis, yet conventional methods often face limitations in sensitivity and operational complexity. Here, we report a label-free biosensor based on a suspended graphene field-effect transistor (GFET) for [...] Read more.

The sensitive detection of microRNA-21 (miR-21), a key biomarker for various cancers, is crucial for early diagnosis, yet conventional methods often face limitations in sensitivity and operational complexity. Here, we report a label-free biosensor based on a suspended graphene field-effect transistor (GFET) for the direct electrical detection of miR-21. The suspended architecture isolates the graphene channel from substrate-induced interference, resulting in enhanced carrier mobility and reduced electrical noise. After surface functionalization with a specific probe, the GFET demonstrated a clear concentration-dependent response to target miR-21. The binding events were transduced into a monotonic increase in relative resistance (ΔR/R₀) and a positive shift of the Dirac point (V_Dirac), achieving a detection limit in the femtomolar (fM) range. These results establish the suspended GFET as a highly sensitive and robust platform for quantifying nucleic acid biomarkers, holding significant potential for biomedical research and point-of-care diagnostics. Full article

(This article belongs to the Section Biosensor Materials)

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14 pages, 2074 KB

Open AccessArticle

Metal-Free Electrochemical Dopamine Sensing Using a g-C₃N₄/Polymethyl Thymol Blue Nanohybrid

by Sankar Sekar, Sejoon Lee, Sutha Sadhasivam, Kumar Sangeetha Selvan, Saravanan Sekar, Youngmin Lee, Pugazhendi Ilanchezhiyan, Seung-Cheol Chang and Ramalingam Manikandan

Biosensors 2026, 16(2), 124; https://doi.org/10.3390/bios16020124 - 17 Feb 2026

Viewed by 184

Abstract

We report a highly sensitive and interference-free electrochemical sensor for dopamine (DA) detection in the presence of uric acid (UA) and ascorbic acid (AA), based on an in situ deposited graphitic carbon nitride (g-C₃N₄) and polymethyl thymol blue (PMTB) [...] Read more.

We report a highly sensitive and interference-free electrochemical sensor for dopamine (DA) detection in the presence of uric acid (UA) and ascorbic acid (AA), based on an in situ deposited graphitic carbon nitride (g-C₃N₄) and polymethyl thymol blue (PMTB) nanohybrid modified screen-printed carbon electrode (SPCE). The as-fabricated g-C₃N₄/PMTB/SPCE was thoroughly characterized using various physicochemical techniques. The electrochemical behavior of the modified electrode was systematically investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The g-C₃N₄/PMTB/SPCE exhibited excellent electrocatalytic activity toward the selective oxidation of DA under optimized experimental conditions, including pH and scan rate. Interference-free detection of DA in the presence of AA and UA was achieved using DPV and chronoamperometric methods, revealing a wide linear concentration range, an ultralow limit of detection, and high sensitivity. Furthermore, the practical applicability of the proposed sensor was validated by determining DA in artificial biofluid samples, including blood serum, and urine. The recovery results obtained good agreement with those obtained using high-performance liquid chromatography (HPLC), confirming the reliability and accuracy of the developed sensing platform. Full article

(This article belongs to the Special Issue Electrochemical Biosensors for Environmental and Food Safety)

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27 pages, 7838 KB

Open AccessReview

Optical Biosensors for Blood Coagulation Monitoring: Advantages, Limitations, and Translational Potential

by Zichen Wang, Gaohong Di and Jing Wang

Biosensors 2026, 16(2), 123; https://doi.org/10.3390/bios16020123 - 16 Feb 2026

Viewed by 178

Abstract

Dynamic monitoring of hemostatic equilibrium is indispensable for clinical safety in high-risk scenarios, while current clinical methods are limited by sample volume, detection speed, and physiological relevance. These shortcomings underscore the demand for novel sensing platforms. Optical biosensors, leveraging label-free detection, rapid response, [...] Read more.

Dynamic monitoring of hemostatic equilibrium is indispensable for clinical safety in high-risk scenarios, while current clinical methods are limited by sample volume, detection speed, and physiological relevance. These shortcomings underscore the demand for novel sensing platforms. Optical biosensors, leveraging label-free detection, rapid response, and multi-level characterization, could serve as a transformative solution for decentralized and point-of-care monitoring. This review systematically summarizes advances in optical coagulation testing, encompassing light transmission aggregometry, laser speckle rheology, optical coherence tomography/elastography, optic–acoustic coupled methods, and fluorescence biosensing. These technologies complementarily capture structural and mechanical and some molecular and cellular dynamics of coagulation, bridging gaps in traditional assays. Despite promising preclinical and clinical correlations, translation barriers persist in lack of standardization of metrics, interference mitigation, and multi-center validation in diverse patient cohorts. Future development of optical biosensing platforms for coagulation testing should focus on modular integration, AI-aided interference correction, and microfluidic miniaturization to realize actionable, real-time coagulation assessment. Optical biosensors hold unparalleled potential to transform hemostatic monitoring from static endpoint testing to dynamic, interpretable evaluation, guiding personalized clinical decisions. Full article

(This article belongs to the Section Optical and Photonic Biosensors)

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14 pages, 2911 KB

Open AccessArticle

Hybrid Oxygen-Sensing Bio-Scaffolds for 3D Micro-Tissue Models

by Liang Li, Alexander V. Zhdanov and Dmitri B. Papkovsky

Biosensors 2026, 16(2), 122; https://doi.org/10.3390/bios16020122 - 14 Feb 2026

Viewed by 207

Abstract

Culturing cells and micro-tissue samples in 3D bio-scaffolding structures is gaining popularity; however, precise control of tissue micro-environment in such systems remains challenging. We describe a family of new hybrid bio-scaffolds with 3D O₂-sensing ability, produced by simple means from readily [...] Read more.

Culturing cells and micro-tissue samples in 3D bio-scaffolding structures is gaining popularity; however, precise control of tissue micro-environment in such systems remains challenging. We describe a family of new hybrid bio-scaffolds with 3D O₂-sensing ability, produced by simple means from readily available bio-scaffolding and O₂-sensing materials. Three different types of phosphorescent O₂-sensing materials—polymeric microparticles (MPs), supramolecular probe MitoXpress and nanoparticulate probes NanO2 and Nano-IR (NPs)—were integrated in Matrigel and agarose scaffolding materials and evaluated. Key working characteristics of such hybrid scaffolds, including heterogeneity, stability, cytotoxicity, optical signals and O₂-sensing properties, ease of fabrication and use, were compared. The results show superiority of the Matrigel hybrids with NanO2 and Nano-IR probes. Demonstration experiments were conducted with HCT116 cells and individual spheroids derived from these cells, culturing them in the Matrigel–NP hybrid scaffolds and monitoring oxygenation and local O₂ gradients on a time-resolved fluorescence plate reader and by phosphorescence lifetime imaging microscopy (PLIM). Full article

(This article belongs to the Section Biosensor Materials)

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15 pages, 1402 KB

Open AccessArticle

In Silico Optimization of a Non-Invasive Optical Sensor for Hemoconcentration Monitoring in Dengue Fever Management

by Murad Althobaiti and Gameel Saleh

Biosensors 2026, 16(2), 121; https://doi.org/10.3390/bios16020121 - 13 Feb 2026

Viewed by 261

Abstract

Severe Dengue fever can cause Dengue Hemorrhagic Fever (DHF), a life-threatening condition characterized by plasma leakage and hemoconcentration. A hematocrit (Hct) rise of ≥20% is a key indicator for medical intervention, but current monitoring is invasive and intermittent. This study aims to determine [...] Read more.

Severe Dengue fever can cause Dengue Hemorrhagic Fever (DHF), a life-threatening condition characterized by plasma leakage and hemoconcentration. A hematocrit (Hct) rise of ≥20% is a key indicator for medical intervention, but current monitoring is invasive and intermittent. This study aims to determine the optimal design parameters for a non-invasive optical sensor to continuously monitor hemoconcentration. We developed a high-fidelity Monte Carlo model of light transport in a multi-layered skin model, with the epidermis set to a 5% melanin volume fraction (Fitzpatrick type II/III). To ensure signal reliability, simulations were conducted with a high photon count (

1 \times 10^{8}

photons), yielding a stochastic (Monte Carlo) signal-to-noise ratio of approximately 36 dB. We simulated diffuse reflectance at four characteristic wavelengths (577 nm, 660 nm, 800 nm—the isosbestic point—, and 940 nm) over source-detector separations of 0.5–8.0 mm. Sensor sensitivity was quantified as the reflectance change for a +25% relative Hct rise (e.g., 42% to 52.5%), mimicking severe hemoconcentration, and its dependence on baseline dermal blood volume fraction (BVF) was investigated. Sensor sensitivity showed a non-linear dependence on BVF, showing a direct correlation with perfusion level, reaching an optimal 6.41% for a robust 5% BVF at 8.0 mm. A dedicated sweep showed that even under low-perfusion shock conditions (1% BVF), the sensor maintains a highly significant sensitivity of 5.71% (also at 8.0 mm), indicating that sensitivity remains high across a physiologically relevant perfusion range. In the analysis, at a robust 5% BVF, the 800 nm wavelength demonstrated superior reliability, with peak sensitivity at 6.41% at 8.0 mm. Visible wavelengths (577 nm and 660 nm) exhibited high theoretical sensitivity, while 940 nm was compromised by water absorption. Based on these findings, a non-invasive optical sensor for hemoconcentration is most effective operating at 800 nm, within the evaluated spectral set, with a source-detector separation of ≥6.0 mm, targeting the deep dermis while minimizing superficial interference. This design provides an optimal balance of tissue penetration, robust sensitivity to Hct changes, and reduced sensitivity to oxygenation-related variability while maintaining signal stability. This work enables the design of a device for continuous monitoring, supporting continuous monitoring of hemoconcentration trends relevant to plasma leakage progression. Full article

(This article belongs to the Section Biosensors and Healthcare)

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24 pages, 3623 KB

Open AccessArticle

Automated Intracellular Immunofluorescence Staining Enabled by Magnetic 3D Mixing in a Modular Microfluidic Platform

by Zhengyi Zhang, Mengyu Wang, Runtao Zhong, Yingbo Zhao and Yeqing Sun

Biosensors 2026, 16(2), 120; https://doi.org/10.3390/bios16020120 - 13 Feb 2026

Viewed by 275

Abstract

Traditional sample preparation for flow cytometry is often labor-intensive, operator-dependent, and reagent-consuming, limiting its suitability for automated and point-of-care biosensing applications. To address these challenges, this study presents a functional modular microfluidic system integrating immunomagnetic beads (IMBs) to enable automated intracellular immunofluorescence (IF) [...] Read more.

Traditional sample preparation for flow cytometry is often labor-intensive, operator-dependent, and reagent-consuming, limiting its suitability for automated and point-of-care biosensing applications. To address these challenges, this study presents a functional modular microfluidic system integrating immunomagnetic beads (IMBs) to enable automated intracellular immunofluorescence (IF) staining. The modular microfluidic platform is enabled by a dynamically actuated three-dimensional magnetic field that couples with IMBs within a microfluidic reaction chamber, requiring only one-dimensional magnet translation to induce effective three-dimensional bead motion. This magnetic–chip cooperative strategy significantly enhances microscale mixing and cell capture, facilitating automated immunostaining of the radiation biomarker in CD4⁺ cells. Finite element simulations were employed to guide magnetic field design by analyzing magnetic force distributions and identifying key parameters, including magnet material, size, spatial arrangement, and chip–magnet distance. Experimental validation using CD4⁺ cell capture confirmed the effectiveness of the magnetic mixing strategy, revealing ∇B·B as the critical design parameter. An N52 NdFeB magnet (6 mm diameter, 10 mm height) positioned within 2.2 mm of the chamber centerline stably retained IMBs at flow rates below 200 µL/min. Under optimized conditions (magnet translation speed of 8 mm/s and a 15 min mixing duration), a maximum cell capture efficiency of 86% was achieved. Subsequent automated γH2AX IF staining demonstrated a strong linear dose–response relationship (R² > 0.9) in mean fluorescence intensity. This study demonstrates a robust and scalable strategy for automating complex IF staining workflows, highlighting the potential of magnetic-field-assisted microfluidic platforms for biosensing applications requiring reliable intracellular biomarker detection. Full article

(This article belongs to the Section Environmental, Agricultural, and Food Biosensors)

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11 pages, 4199 KB

Open AccessArticle

Deep Convolutional Neural Networks for Autofocus Control on a C. elegans Tracking System

by Santiago Escobar-Benavides, Jose-Julio Peñaranda-Jara, Joan-Carles Puchalt and Antonio-José Sánchez-Salmerón

Biosensors 2026, 16(2), 119; https://doi.org/10.3390/bios16020119 - 12 Feb 2026

Viewed by 230

Abstract

Correct focal positioning is essential for microscopy imaging of live moving subjects such as Caenorhabditis elegans. However, many methods can be too slow to perform real-time control to keep the subject in focus. In this work, we propose a convolutional neural network-based [...] Read more.

Correct focal positioning is essential for microscopy imaging of live moving subjects such as Caenorhabditis elegans. However, many methods can be too slow to perform real-time control to keep the subject in focus. In this work, we propose a convolutional neural network-based method to perform one-shot prediction of the optimal focusing distance, without the need to scan iteratively the optical axis to find the optimal position. A new data augmentation technique is proposed, and its effectiveness is validated through statistical analysis. This technique is shown to improve results without the need for additional data collection. Several architectures are trained in z-stacks of images, using the proposed data augmentation technique, and compared on a validation set. Through this comparison, we find that the ConvNext V2, a novel architecture in this context, outperforms other models proposed in previous works. Furthermore, the impact of the Field of View used for the model’s prediction is studied, with the aim of further understanding the influence of spatial resolution and spatial compression on the performance of the model. Full article

(This article belongs to the Section Biosensors and Healthcare)

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52 pages, 2563 KB

Open AccessReview

Biosensor Technologies for Avian Influenza Detection: A New Frontier in Rapid Diagnostics for HPAI

by Jacquline Risalvato, Alaa H. Sewid, Durina Z. Dalrymple, Shigetoshi Eda, J. Jayne Wu and Richard W. Gerhold

Biosensors 2026, 16(2), 118; https://doi.org/10.3390/bios16020118 - 12 Feb 2026

Viewed by 519

Abstract

Avian influenza (AI), particularly highly pathogenic avian influenza (HPAI), represents a serious and growing threat to global poultry production, international trade, and human health security. Control of AI is complicated by the high evolutionary rate of influenza A viruses, which drives antigenic diversity [...] Read more.

Avian influenza (AI), particularly highly pathogenic avian influenza (HPAI), represents a serious and growing threat to global poultry production, international trade, and human health security. Control of AI is complicated by the high evolutionary rate of influenza A viruses, which drives antigenic diversity and ongoing emergence of novel strains. Effective surveillance and disease management therefore depend on timely and accurate diagnostics. While conventional methods—including virus isolation, reverse transcription-quantitative polymerase chain reaction (RT-qPCR), and enzyme-linked immunosorbent assays (ELISAs)—remain effective and widely used, they are limited by long turnaround times, the need for specialized equipment, and reliance on highly trained personnel. In addition, strict state and federal regulatory requirements restrict testing to a limited number of authorized laboratories. Although these regulations are essential for maintaining diagnostic accuracy and quality assurance, they place substantial strain on laboratory capacity during outbreaks and delay actionable results. The need for rapid, on-site decision making has driven interest in alternative diagnostic approaches, including biosensor technologies. A major limitation of current diagnostic strategies is the lack of robust DIVA (Differentiating Infected from Vaccinated Animals) capability. In countries such as the United States, where poultry vaccination against AI is not routinely practiced, the absence of DIVA-compatible diagnostics has hindered adoption of vaccination as a disease management tool, as seropositive birds and products face significant trade restrictions. Biosensor platforms capable of enabling DIVA strategies offer a potential pathway to support vaccination while preserving surveillance integrity. This review examines the current landscape of AI and HPAI diagnostics, emphasizing the limitations of traditional approaches and the opportunities presented by biosensor platforms. We evaluate electrochemical, optical, piezoelectric, and nucleic-acid-based biosensors, with particular attention to biorecognition strategies, performance metrics, field deployability, and applications supporting subtype discrimination, DIVA implementation, and One Health surveillance. Full article

(This article belongs to the Special Issue Advanced Sensors for the Detection of Viruses, Bacteria and Biomarkers)

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4 pages, 161 KB

Open AccessEditorial

CRISPR/Cas System-Based Biosensors

by Xingjie Hu, Jing Su and Shiping Song

Biosensors 2026, 16(2), 117; https://doi.org/10.3390/bios16020117 - 10 Feb 2026

Viewed by 278

Abstract

Over the past decade, clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated (Cas) proteins, originally identified as adaptive immune systems in bacteria and archaea that defend against invading nucleic acids, have revolutionized biological research [...] Full article

(This article belongs to the Special Issue CRISPR/Cas System-Based Biosensors)

12 pages, 2068 KB

Open AccessArticle

Chemiluminescent Biosensor Utilizing Magnetic Particles for the Detection of Ovarian Cancer Biomarker Lysophosphatidic Acid

by Navina Lotay and Michael Thompson

Biosensors 2026, 16(2), 116; https://doi.org/10.3390/bios16020116 - 10 Feb 2026

Viewed by 320

Abstract

Lysophosphatidic acid (LPA) is a cell-signaling lipid that has been proposed as an early-stage biomarker for ovarian cancer (OC). Diagnosing OC in Stage I is critical to improving patient outcomes, increasing the survival rate from 30% (when diagnosed in late stages of the [...] Read more.

Lysophosphatidic acid (LPA) is a cell-signaling lipid that has been proposed as an early-stage biomarker for ovarian cancer (OC). Diagnosing OC in Stage I is critical to improving patient outcomes, increasing the survival rate from 30% (when diagnosed in late stages of the disease) to over 90%. This significant improvement is due to the success of early interventions; however, current diagnostic methods are not as effective at early-stage detection, with only 15% of cases diagnosed in Stage I and over 70% diagnosed in Stage III or IV. There is a strong need for LPA detection that is sensitive, specific, rapid, low-cost, and automated to truly validate its effectiveness as a diagnostic characteristic for OC. We report the preliminary development and characterization of one such biosensor, which makes use of the advantages of magnetic particles and chemiluminescence for quick, sensitive detection of LPA. The sensor has proven to be viable, with a positive response to LPA concentration, a measurement time of 5 s after incubation, and an LOD of 3.5 nM. Full article

(This article belongs to the Special Issue Innovative Strategies for Cancer Biosensing)

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16 pages, 3894 KB

Open AccessArticle

Evaluation of Activated Biochar Derived from Sargassum spp. as a Sustainable Substrate for the Development of Electrochemical DNA Biosensing

by Jorge A. Campoy-Ramírez, Nikola Batina, Mauricio Castañón-Arreola, Eduardo O. Madrigal-Santillán, José A. Morales-González, Javier Jiménez-Salazar, Pablo Damián-Matsumura, José G. Téllez, Xariss M. Sánchez-Chino, Berenice Carbajal-López, Abraham Cetina-Corona, José A. Garcia-Melo and Luis Fernando Garcia-Melo

Biosensors 2026, 16(2), 115; https://doi.org/10.3390/bios16020115 - 10 Feb 2026

Viewed by 287

Abstract

This study aims to develop an innovative electrochemical genosensor based on activated biochar (ABC) derived from the biomass of the seaweed Sargassum spp. The synthesis process begins with the pyrolysis of Sargassum spp. at 500 °C to obtain biochar (BC), which [...] Read more.

This study aims to develop an innovative electrochemical genosensor based on activated biochar (ABC) derived from the biomass of the seaweed Sargassum spp. The synthesis process begins with the pyrolysis of Sargassum spp. at 500 °C to obtain biochar (BC), which is chemically activated with nitric acid (HNO₃). The physicochemical properties of the resulting material, such as morphology and surface area, were characterized using techniques including scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and the Brunauer–Emmett–Teller (BET) method for surface area. BET results showed an increase in surface area from 22.9367 ± 0.0879 m²/g (BC) to 159.2915 ± 2.2641 m²/g (ABC). For the development of the genosensor, a hydrolyzed collagen gel matrix enriched with ABC is created. This nanostructured, biocompatible mixture is used to immobilize a DNA probe on a graphite electrode, employing the large surface area of ABC and the formation of a functional HC-based coating. The system’s viability was evaluated by cyclic voltammetry (CV), which showed changes in the maximum anodic peak current (Ipa) during fabrication: 27.78 ± 1.87 μA for the bare electrode, 35.25 ± 1.24 μA for ABC 30%, and 39.25 ± 1.84 μA for HC + ABC 30%. After ssDNA immobilization and hybridization to dsDNA, Ipa decreased to 28.81 ± 1.565 μA and 23.10 ± 1.25 μA, respectively. Finally, hematoxylin (Hx) was used as an intercalating indicator from hybridization, reducing the maximum anodic peak current to 15.51 ± 1.13 μA, consistent with additional interfacial limitations associated with dsDNA formation. Overall, the developed system demonstrates a sustainable, promising platform for molecular diagnostics in electrochemical DNA biosensor development. Full article

(This article belongs to the Special Issue Advanced Materials for Electrochemical Sensors and Biosensors Development—2nd Edition)

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15 pages, 1772 KB

Open AccessArticle

Polystyrene Microsphere-Labeled Lateral Flow Assay for the Visual Detection of Foodborne Pathogens

by Lingmei Zhang, Wanwei Qiu, Lu Lu, Jinghui Liu, Zhipeng Zou, Litao Yang and Haobo Sun

Biosensors 2026, 16(2), 114; https://doi.org/10.3390/bios16020114 - 10 Feb 2026

Viewed by 266

Abstract

With the increasing emphasis on food safety and health, it has become particularly important to develop rapid, sensitive and low-cost detection methods for foodborne pathogens. Lateral flow assay (LFA) has shown great potential in the field of point-of-care testing (POCT) due to its [...] Read more.

With the increasing emphasis on food safety and health, it has become particularly important to develop rapid, sensitive and low-cost detection methods for foodborne pathogens. Lateral flow assay (LFA) has shown great potential in the field of point-of-care testing (POCT) due to its rapidity, portability and low cost. However, traditional gold nanoparticles (AuNPs)-labeled LFAs face challenges such as insufficient signal strength when detecting nucleic acids. In this study, LFA labeled with polystyrene microspheres was constructed targeting the specific nuc gene of Staphylococcus aureus for the detection of double-stranded PCR products. Unlike traditional AuNPs that pair antibodies through physical adsorption, polystyrene microspheres adopt a covalent coupling strategy, significantly enhancing probe stability and signal strength. Under the optimized conditions, the detection limit was calculated to be 7.28 × 10² CFU/mL, which was approximately 10 times higher than that of the AuNP-based strip. This method demonstrated excellent specificity, reproducibility (RSD < 5%) and stability. In the practical application of artificially contaminated milk samples, the detection performance of polystyrene microsphere-based strips was better than that of AuNP-based strips. This study provides an efficient and easy-to-operate solution for the visual detection of foodborne pathogens. Full article

(This article belongs to the Special Issue Advanced Biosensors Based on Molecular Recognition)

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13 pages, 1710 KB

Open AccessArticle

Inkjet-Printed Electrode Enable Portable Electrochemical Immunosensing of Tau-441 for Early Alzheimer’s Screening

by Binglun Li, Chenghao Liu, Chenlu Gu, Shanshan Wei, Shiyong Li, Ziang Liu, Dongdong Zhao, Qunfeng Tang, Yun Chen and Zhencheng Chen

Biosensors 2026, 16(2), 113; https://doi.org/10.3390/bios16020113 - 10 Feb 2026

Viewed by 289

Abstract

Early diagnosis of Alzheimer’s disease represents a critical clinical challenge, and the high-sensitive biomarkers measurement holds great potential for enabling early identification and intervention. This study proposes an electrochemical immunosensing strategy based on inkjet printing for the quantitative detection of Tau-441. Conductive patterns [...] Read more.

Early diagnosis of Alzheimer’s disease represents a critical clinical challenge, and the high-sensitive biomarkers measurement holds great potential for enabling early identification and intervention. This study proposes an electrochemical immunosensing strategy based on inkjet printing for the quantitative detection of Tau-441. Conductive patterns were formed by inkjet printing, followed by surface functionalization with gold nanoparticles to immobilize highly specific anti-Tau-441. This process created a stable and high affinity immunorecognition interface that enhances electron transfer and signal amplification. Furthermore, we developed and integrated a low-power portable detection platform to achieve a rapid detection process encompassing sample loading, signal acquisition, and on-device readout. The method shows a linear response from 50 fg/mL to 10 ng/mL and a limit of detection of 16 fg/mL (S/N = 3), with high specificity and good reproducibility. By combining scalable inkjet fabrication with a self-contained handheld reader, this method shortens the path from sample to result and offers a practical route for on-site screening and early intervention in Alzheimer’s disease. Full article

(This article belongs to the Special Issue Biosensors for Healthcare and Environment: Current and Future Perspectives)

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33 pages, 1625 KB

Open AccessReview

Commercial Translation of Electrochemical Biosensors: Supply Chain Strategy, Scale-Up Manufacturing, and Regulatory–Quality Considerations

by Gao Zhou and Haibin Liu

Biosensors 2026, 16(2), 112; https://doi.org/10.3390/bios16020112 - 9 Feb 2026

Viewed by 375

Abstract

Electrochemical biosensors have reached a high degree of analytical maturity; however, only a small portion of laboratory demonstrations actually progress to commercial products. In this review, we looked non-analytically at the factors which are in place with respect to this translational gap, specifically [...] Read more.

Electrochemical biosensors have reached a high degree of analytical maturity; however, only a small portion of laboratory demonstrations actually progress to commercial products. In this review, we looked non-analytically at the factors which are in place with respect to this translational gap, specifically looking into supply chain design, scale-up manufacturing strategy, regulatory–quality, and more. Based on a wide range of academic and industrial literature, the paper considers how decisions about what kind of material to use, especially for material that recognizes living things, conductive material made from ink, and the material that is the actual product being made, can make a big difference in whether the product can be reproduced easily, if it will stay stable for a long time, and if it is allowed according to the rules. This review compares the dominant manufacturing paradigms—roll-to-roll printing, and semiconductor-derived microfabrication—and shows how the respective strengths and limitations match the different targets, costs, and risk class. This is more about making manufacturing an upstream optimization problem than treating processes as defects and quality as assurance, rather than making it an upstream optimization problem. And it does this by looking at some other big pathways for regulations in the U.S., EU, and China as well, where we get to see how those differences in classification requirements, what kind of proofs you should have, and different ways about running those quality management systems affect how quickly things can come out after developing them, and what your flexibility with customers is like when those products are already out there in the world. The study looks at some case studies: disposable glucose strips, cartridge-based blood analyzers, and new continuous monitoring systems are used to show how the exact same electrochemical ideas can result in very different commercialization issues based on the clinical context and system integration. Synthesizing those angles creates a review that can give a system level map of matching research design to industrial and regulatory realities, with the goal of making it easier for electrochemical biosensors to go from lab prototypes to ready-for-market diagnostic tools. Full article

(This article belongs to the Special Issue Advanced Electrochemical Biosensors and Their Applications)

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12 pages, 1880 KB

Open AccessArticle

Highly Sensitive Fluorescent Detection of HPV-16 DNA Using Tungsten Disulfide Nanosheets and Exonuclease III-Assisted Signal Amplification

by Miaoxing Wu, Guan Lin, Jingyi Dong, Aolan Zeng, Huibo Hong, Zheng Chen and Chengyi Hong

Biosensors 2026, 16(2), 111; https://doi.org/10.3390/bios16020111 - 9 Feb 2026

Viewed by 213

Abstract

This study addresses the need for detecting human papillomavirus type 16 DNA (HPV-16), a high-risk factor for cervical cancer, by developing a highly sensitive fluorescence sensing method based on tungsten disulfide (WS₂) nanosheets and exonuclease III (EXO III)-assisted cyclic amplification. The [...] Read more.

This study addresses the need for detecting human papillomavirus type 16 DNA (HPV-16), a high-risk factor for cervical cancer, by developing a highly sensitive fluorescence sensing method based on tungsten disulfide (WS₂) nanosheets and exonuclease III (EXO III)-assisted cyclic amplification. The method is constructed by combining the highly efficient fluorescence quenching capability of tungsten disulfide (WS₂) nanosheets with a fluorescein (FAM)-labeled complementary DNA (cDNA) probe. When the target HPV-16 is present, it specifically hybridizes with the cDNA to form a double-stranded structure. This double-stranded structure can be cleaved by EXO III. The cleaved cDNA is not adsorbed by WS₂ nanosheets, generating a significant fluorescence signal. The released HPV-16 can then participate in the reaction again, achieving multiple rounds of fluorescence signal amplification. Under optimal conditions, the detection limit of the method is 0.35 pM. The method was successfully applied to the detection of HPV-16 in spiked serum samples, demonstrating the advantages of operational simplicity, high sensitivity, and good specificity. It provides a promising rapid detection method for clinical application research related to human papillomavirus. Full article

(This article belongs to the Special Issue Point-of-Care Testing Using Biochemical Sensors for Health and Safety)

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39 pages, 8743 KB

Open AccessReview

A Review of Aggregation-Based Colorimetric and SERS Sensing of Metal Ions Utilizing Au/Ag Nanoparticles

by Shu Wang, Lin Yin, Yanlong Meng, Han Gao, Yuhan Fu, Jihui Hu and Chunlian Zhan

Biosensors 2026, 16(2), 110; https://doi.org/10.3390/bios16020110 - 8 Feb 2026

Viewed by 324

Abstract

The accurate monitoring and dynamic analysis of metal ions are of considerable practical significance in environmental toxicology and life sciences. Colorimetric analysis and surface-enhanced Raman scattering (SERS) sensing technologies, utilizing the aggregation effect of gold and silver nanoparticles (Au/Ag NPs), have emerged as [...] Read more.

The accurate monitoring and dynamic analysis of metal ions are of considerable practical significance in environmental toxicology and life sciences. Colorimetric analysis and surface-enhanced Raman scattering (SERS) sensing technologies, utilizing the aggregation effect of gold and silver nanoparticles (Au/Ag NPs), have emerged as prominent methods for rapid metal ion detection. While sharing a common plasmonic basis, these two techniques serve distinct yet complementary analytical roles: colorimetric assays offer rapid, instrument-free visual screening ideal for point-of-care testing (POCT), whereas SERS provides superior sensitivity and structural fingerprinting for precise quantification in complex matrices. Furthermore, the synergistic integration of these modalities facilitates the development of dual-mode sensing platforms, enabling mutual signal verification for enhanced reliability. This article evaluates contemporary optical sensing methodologies utilizing aggregation effects and their advancements in the detection of diverse metal ions. It comprehensively outlines methodological advancements from nanomaterial fabrication to signal transduction, encompassing approaches such as biomass-mediated green synthesis and functionalization, targeted surface ligand engineering, digital readout systems utilizing intelligent algorithms, and multimodal synergistic sensing. Recent studies demonstrate that these techniques have attained trace-level identification of target ions regarding analytical efficacy, with detection limits generally conforming to or beyond applicable environmental and health safety regulations. Moreover, pertinent research has enhanced detection linear ranges, anti-interference properties, and adaptability for POCT, validating the usefulness and developmental prospects of this technology for analysis in complicated matrices. Full article

(This article belongs to the Section Optical and Photonic Biosensors)

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22 pages, 4296 KB

Open AccessArticle

Development of Advanced Nanobiosensors and a Portable Monitoring System for Pesticide Detection at the Point of Need

by Evangelos Skotadis, Menelaos Tsigkourakos, Emmanouil Anthoulakis, Myrto-Kyriaki Filippidou, Sotirios Ntouskas, Maria Kainourgiaki, Charalampos Tsioustas, Chrysi Panagopoulou, Stergios Dimou-Sakellariou, Nikos Kalatzis, Eleftherios A. Petrakis, Nikolaos Alexis, George Tsekenis, Angeliki Tserepi, Stavros Chatzandroulis and Dimitris Tsoukalas

Biosensors 2026, 16(2), 109; https://doi.org/10.3390/bios16020109 - 7 Feb 2026

Viewed by 278

Abstract

This work presents the development of an automated and portable monitoring system for the point-of-need detection of tebuconazole and lambda-cyhalothrin. The system features nanoparticle/aptamer-modified electrochemical sensors that are integrated into a microfluidic chip based on polydimethylsiloxane (PDMS). More specifically, rapid and selective detection [...] Read more.

This work presents the development of an automated and portable monitoring system for the point-of-need detection of tebuconazole and lambda-cyhalothrin. The system features nanoparticle/aptamer-modified electrochemical sensors that are integrated into a microfluidic chip based on polydimethylsiloxane (PDMS). More specifically, rapid and selective detection of both pesticides is achieved using target-specific aptamers immobilized on two-dimensional platinum nanoparticle films that serve as expanded nano-gapped electrodes to enhance sensor sensitivity. The effect of the device substrate (i.e., silicon versus flexible substrates) and measurement setup on biosensing performance has also been investigated. The final monitoring system is characterized by high sensitivity and selectivity in the cases of both target analytes and substrates. Τhe system features a limit of detection of 9.85 pM for tebuconazole, which is one of the lowest reported values in the literature; for lambda-cyhalothrin, it is worth noting that the results reported herein represent one of the few studies on an electrochemical aptamer-based sensor for this analyte, featuring a limit of detection of 48.5 pM. The system is also capable of selectively detecting both targets for complex cross-reactive sample matrices consisting of commercially available pesticides. Moreover, its use could be expanded to detect additional pollutants by functionalizing the biosensor surface with appropriate aptamers. Full article

(This article belongs to the Special Issue Nanotechnology Biosensing in Bioanalysis and Beyond)

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17 pages, 3951 KB

Open AccessArticle

Development of a Flexible Microneedle Array Electrode with a High Signal-to-Noise Ratio for Surface Bioelectrical Signal Recording

by Bo Jiang, Ye Wang, Ruiqing Li, Yan Zhou, Lihua Ma, Dingjie Suo and Guangying Pei

Biosensors 2026, 16(2), 108; https://doi.org/10.3390/bios16020108 - 7 Feb 2026

Viewed by 274

Abstract

Microneedle array (MNA) electrodes have garnered significant attention for their capacity to record high-fidelity surface bioelectrical signals over extended periods and convenience. However, accuracy limitations in 3D-printed metal MNA electrodes, particularly concerning surface roughness and insufficient tip sharpness, have been reported. Additionally, the [...] Read more.

Microneedle array (MNA) electrodes have garnered significant attention for their capacity to record high-fidelity surface bioelectrical signals over extended periods and convenience. However, accuracy limitations in 3D-printed metal MNA electrodes, particularly concerning surface roughness and insufficient tip sharpness, have been reported. Additionally, the prevalent use of nonporous metal substrates often results in poor flexibility. This study proposes a novel MNA electrode featuring a lightweight flexible substrate and sharp, smooth microneedles. Utilizing micron-level metal 3D printing with 316L stainless steel, we fabricated the electrodes in a single step. We evaluated the MNA electrode-skin interface impedance via frequency sweep and assessed mechanical properties using porcine skin, followed by the collection and analysis of bioelectrical signals. The results demonstrate that the contact impedance of the MNA electrode is comparable to that of standard gold cup electrodes, with validated flexibility and strength. Furthermore, the MNA electrodes achieved a high signal-to-noise ratio and minimal motion artifacts during recording, thereby enhancing both comfort and signal quality. The efficient production process facilitates the broader application of metal MNA electrodes. Full article

(This article belongs to the Special Issue Recent Advances in Microneedle Array Electrodes in Biomedicine)

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44 pages, 3809 KB

Open AccessReview

Electrochemical (Bio)Sensors Based on Nanotechnologies for the Detection of Important Biomolecules in Plants and Plant-Related Samples: The Future of Smart and Precision Agriculture

by Ioana Silvia Hosu, Radu-Claudiu Fierăscu and Irina Fierăscu

Biosensors 2026, 16(2), 107; https://doi.org/10.3390/bios16020107 - 6 Feb 2026

Viewed by 250

Abstract

Considering the present environmental concerns, nanomaterial-based methods should be applied to achieve the bioeconomic sustainability initiatives and climate change mitigation. Plants and plant extracts are one of the most underused biomass and bioactive ingredients resources. Moreover, nowadays crop loss is one of the [...] Read more.

Considering the present environmental concerns, nanomaterial-based methods should be applied to achieve the bioeconomic sustainability initiatives and climate change mitigation. Plants and plant extracts are one of the most underused biomass and bioactive ingredients resources. Moreover, nowadays crop loss is one of the main problems that the world faces, together with the depletion of natural resources, increasing population and limited arable land, leading to increased food scarcity and demand. To correctly attribute/use plant-based bioresources or to rapidly decide which farming operations should be performed before crop loss, we should be able to properly characterize plants or plant-based resources by the desired useful characteristics, such as (bio)chemical characteristics, rather than simply observing physical traits of plants (because, when these traits become visible, it may be too late for crop loss mitigation). Plant crops could be optimized, for example, using electrochemical methods that assess the nutrient uptake and nutrient use efficiency (NUE) or the oxidative stress burst encountered before crop loss, in order to improve crop yields and crop quality. Other different important analytes (such as hormones, pathogens, metabolites, etc.) or plant characteristics (such as genus, species, phylogenetic analysis, etc.) can be evaluated with these electrochemical sensors and methods. In the present review, we focus on the application of nanomaterials/nanotechnologies for the development of fast, accurate, accessible, cost-effective, sensitive and selective analytical electrochemical methods for the detection of different relevant biomolecules in plants or plant-related samples (plant extracts, plant cells, plant tissues, and/or plant-derived natural drinks/foods, as well as entire plants/plant parts), both in vivo vs. ex vivo and in situ vs. ex situ. This review systematically presents and critically discusses the outcomes of current electrochemical methods (both applied in the lab or as wearable/implantable sensors) and the future perspectives of these nanotechnology-based sensors, with an accent on wearable sensors for smart and precision agriculture, as real-world sensing technologies with significant practical impact. The novelty of this article is the abundance of electrochemical analytical parameters gathered and discussed, for such a large number of analyte categories. Full article

(This article belongs to the Special Issue Electrochemical (Bio)Sensors as Promising Analytical Tools in the Analysis of Soils, Plants and Environmental Monitoring)

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15 pages, 1780 KB

Open AccessArticle

Rapid Forensic DNA Profiling via Real-Time Recombinase Polymerase Amplification of InDel Markers

by Liesl De Keyzer, Sonja Škevin, Koen Deserranno, Dieter Deforce and Filip Van Nieuwerburgh

Biosensors 2026, 16(2), 106; https://doi.org/10.3390/bios16020106 - 6 Feb 2026

Viewed by 355

Abstract

Forensic DNA profiling commonly relies on polymerase chain reaction (PCR) amplification followed by capillary electrophoresis (CE) or massively parallel sequencing (MPS), which requires expensive, laboratory-based equipment that depends on a stable power supply and is unsuitable for field applications. Here, we present a [...] Read more.

Forensic DNA profiling commonly relies on polymerase chain reaction (PCR) amplification followed by capillary electrophoresis (CE) or massively parallel sequencing (MPS), which requires expensive, laboratory-based equipment that depends on a stable power supply and is unsuitable for field applications. Here, we present a proof-of-concept assay that uses recombinase polymerase amplification (RPA) combined with exo probe detection for rapid, isothermal genotyping of insertion–deletion (InDel) markers. To the best of our knowledge, this study represents the first demonstration of forensic DNA typing using RPA coupled with exo probes. The reaction proceeds at 39 °C and combines amplification and detection in a single 20 min step. Thirteen DNA samples were genotyped in triplicate across eight InDel loci using allele-specific fluorescent probes. Genotypes were derived from differential endpoint fluorescence between matched and mismatched probes. Compared with benchmark genotyping, 97.07% of genotypes (n = 307) were correct at 1 ng DNA input. Accurate profiles were reliably obtained for DNA inputs as low as 250 pg, and partial profiles were still detectable at 31 pg. The results demonstrate that RPA-based InDel genotyping is fast, sensitive, and reproducible. With further optimization, such as refined probe design and selection of robust loci, the assay has clear potential to achieve complete accuracy and to be integrated into portable lab-on-a-chip platforms for rapid, field-deployable forensic identification. Full article

(This article belongs to the Section Biosensor and Bioelectronic Devices)

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12 pages, 6121 KB

Open AccessArticle

Upconversion Nanoparticle-Based Luminescence DNA Sensor on Porous Silicon Substrate

by Yangzhi Zhang, Xingyu Wang, Yajun Liu, Zhenhong Jia, Ziyi Yang, Xiaohui Huang and Jiajia Wang

Biosensors 2026, 16(2), 105; https://doi.org/10.3390/bios16020105 - 6 Feb 2026

Viewed by 225

Abstract

Rare-earth-doped upconversion nanoparticles (UCNPs) exhibit upconversion luminescence upon excitation with infrared light and have been extensively utilized in the field of biosensing. In this study, a UCNPs-based biosensor with porous silicon (PSi) as the substrate was developed for the first time, enabling the [...] Read more.

Rare-earth-doped upconversion nanoparticles (UCNPs) exhibit upconversion luminescence upon excitation with infrared light and have been extensively utilized in the field of biosensing. In this study, a UCNPs-based biosensor with porous silicon (PSi) as the substrate was developed for the first time, enabling the detection of target DNA molecule concentration. First, a PSi substrate was prepared via electrochemical etching and subsequently functionalized to enable target DNA molecules to immobilize onto the inner walls of the PSi substrate’s pores. Then, UCNPs-labeled probe DNA molecules hybridized with the target DNA molecules, enabling indirect attachment of UCNPs to the inner walls of the PSi substrate. Subsequently, the sample surface is irradiated with a 980 nm laser. Upconversion fluorescence images of the sample, both before and after the biological reaction, are captured using an image acquisition device. Image processing software is employed to calculate the average change in grayscale values, enabling the determination of the molecular concentration of target DNA. The limit of detection (LOD) of this method for target DNA molecular concentration is 86 pM, demonstrating that it enables low-cost, highly sensitive, rapid, and convenient biological detection of target DNA molecules. Full article

(This article belongs to the Special Issue Photonics for Bioapplications: Sensors and Technology—2nd Edition)

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29 pages, 1087 KB

Open AccessReview

Recent Advances in Microfluidic Chip Technology for Laboratory Medicine: Innovations and Artificial Intelligence Integration

by Hong Cai, Dongxia Wang, Yiqun Zhao and Chunhui Yang

Biosensors 2026, 16(2), 104; https://doi.org/10.3390/bios16020104 - 5 Feb 2026

Viewed by 760

Abstract

Microfluidic chip technologies, also known as lab-on-a-chip systems, have profoundly transformed laboratory medicine by enabling the miniaturization, automation, and rapid processing of complex diagnostic assays using minimal sample volumes. Recent advances in chip design, fabrication methods—including 3D printing, modular and flexible substrates—and biosensor [...] Read more.

Microfluidic chip technologies, also known as lab-on-a-chip systems, have profoundly transformed laboratory medicine by enabling the miniaturization, automation, and rapid processing of complex diagnostic assays using minimal sample volumes. Recent advances in chip design, fabrication methods—including 3D printing, modular and flexible substrates—and biosensor integration have significantly enhanced the performance, sensitivity, and clinical applicability of these devices. Integration of advanced biosensors allows for real-time detection of circulating tumor cells, nucleic acids, and exosomes, supporting innovative applications in cancer diagnostics, infectious disease detection, point-of-care testing (POCT), personalized medicine, and therapeutic monitoring. Notably, the convergence of microfluidics with artificial intelligence (AI) and machine learning has amplified device automation, reliability, and analytical power, resulting in “smart” diagnostic platforms capable of self-optimization, automated analysis, and clinical decision support. Emerging applications in fields such as neuroscience diagnostics and microbiome profiling further highlight the broad potential of microfluidic technology. Here, we present findings from a comprehensive review of recent innovations in microfluidic chip design and fabrication, advances in biosensor and AI integration, and their clinical applications in laboratory medicine. We also discuss current challenges in manufacturing, clinical validation, and system integration, as well as future directions for translating next-generation microfluidic technologies into routine clinical and public health practice. Full article

(This article belongs to the Section Biosensors and Healthcare)

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