Biosensors

20 pages, 5811 KB

Open AccessArticle

A Multimodal Time Point Labeling Approach for Analyzing Mastication and Swallowing Dynamics

by Jingjing Liu, Yuxuan Cao, Jiale Kuang, Zhongren Wei, Boyu Liu, Xianghao Wu, Bolin Shi, Lei Zhao, Dongfu Xu, Xinyu Wang and Kui Zhong

Biosensors 2026, 16(5), 301; https://doi.org/10.3390/bios16050301 - 21 May 2026

Viewed by 771

Abstract

Mastication and swallowing are complex physiological processes involving the coordinated activity of multiple tissues in the oral cavity, facial region, and laryngeal system. Some detection methods suffer from limitations such as insufficient information acquisition and inadequate temporal feature analysis. To address these issues, [...] Read more.

Mastication and swallowing are complex physiological processes involving the coordinated activity of multiple tissues in the oral cavity, facial region, and laryngeal system. Some detection methods suffer from limitations such as insufficient information acquisition and inadequate temporal feature analysis. To address these issues, this study proposes a conceptual method for analyzing the state of masticatory and swallowing movements. It integrates maxillofacial electromyographic (EMG) signals with laryngeal movement signals. The goal is to preliminarily explore state analysis of masticatory and swallowing movements over time. A designed gain-adjustable conditioning circuit processes and acquires these signals: maxillofacial EMG signals from EMG electrodes and laryngeal movement signals from flexible PVDF piezoelectric sensors. These two signal streams complement each other’s missing information, enabling comprehensive detection of the state of masticatory and swallowing movements. To address time-point labeling in mastication and swallowing, a sliding-window-based dispersion calculation method was employed to extract characteristic signal nodes, which were then accurately associated with their corresponding physiological motion states. We combined temporal features such as the zero point, onset of fluctuations, characteristic peaks, and baseline recovery from electromyographic (EMG) signals and laryngeal movement signals. This allowed us to establish a correspondence between key time points in the mastication and swallowing processes. The coefficient of determination (R²) for the pressure–voltage linear fit of the PVDF flexible piezoelectric sensor was 0.99446. The pressure resolution was approximately 0.08 kPa. Response times were no more than 15 ms for the EMG channel and no more than 10 ms for the PVDF pressure channel. These results indicate that this method is feasible for extracting oral movement time parameters in healthy subjects. Full article

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

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31 pages, 2459 KB

Open AccessArticle

Smart Bandage Based on Batteryless NFC for Wireless Pressure and Wound State Monitoring

by Marco Cujilema, Ramon Villarino, David Girbau and Antonio Lazaro

Biosensors 2026, 16(5), 300; https://doi.org/10.3390/bios16050300 - 21 May 2026

Cited by 1 | Viewed by 1739

Abstract

Although compression therapy is widely used to improve wound healing, selecting the appropriate pressure remains a challenge in clinical practice. This work proposes an intelligent patch integrated into a bandage that allows for the simultaneous monitoring of the applied pressure and wound condition [...] Read more.

Although compression therapy is widely used to improve wound healing, selecting the appropriate pressure remains a challenge in clinical practice. This work proposes an intelligent patch integrated into a bandage that allows for the simultaneous monitoring of the applied pressure and wound condition using Near-Field Communication (NFC). The proposed patch integrates a force-sensitive resistive sensor to measure pressure and a capacitive sensor to detect wound exudate through capacitance variations. Capacitance is obtained by analyzing the delay in the stepwise response of the sensor, while resistance is measured from the voltage drop across a resistive divider, which is read by a microcontroller’s analog-to-digital converter. The system is powered wirelessly through NFC energy harvesting, triggered by a mobile device that acts as a reader. The NFC module can be moved away after measurement to improve patient comfort or remain integrated into the dressing for periodic monitoring. Experimental results demonstrate pressure measurements up to 140 mmHg and exudate detection up to 200

μ

L, confirming the feasibility of battery-free NFC smart bandages for therapeutic monitoring based on wound compression. Full article

(This article belongs to the Special Issue Nanobiosensors Based on Electrochemical Principles)

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19 pages, 3646 KB

Open AccessArticle

Catalytic Reduction of H₂O₂ by Polyvinylpyrrolidone Nickel Oxide Nanozymatic Activity and Colorimetric Sensing of Ascorbic Acid

by Mosebudi Rambevha, Ridge Chavalala and Philani Mashazi

Biosensors 2026, 16(5), 299; https://doi.org/10.3390/bios16050299 - 21 May 2026

Viewed by 673

Abstract

Ascorbic acid (AA) or vitamin C is an important biomolecule that plays a crucial role in biological and physiological systems. Deficiency and/or excess of AA in the body can lead to severe diseases such as scurvy and gastrointestinal complications. Therefore, it is crucial [...] Read more.

Ascorbic acid (AA) or vitamin C is an important biomolecule that plays a crucial role in biological and physiological systems. Deficiency and/or excess of AA in the body can lead to severe diseases such as scurvy and gastrointestinal complications. Therefore, it is crucial to monitor the levels of AA in the body and supplements. Polyvinylpyrrolidone nickel oxide nanoparticles (PVP-NiONPs) are prepared and evaluated for their potential as nanozymes with peroxidase-like activity. o-Phenylenediamine (OPD) was used as a chromogen in the presence of hydrogen peroxide. The oxidized OPD was produced by ROS from PVP-NiONPs and H₂O₂. This was monitored using UV-vis spectra and by colour changes using the naked eye. AA reduced the oxidized OPD during its sensing. The UV-vis signal was linear for AA concentrations ranging from 40 µM to 400 μM. The limit of detection (LOD) for AA was calculated to be 0.11 μM using 3σ and the limit of quantification (LOQ) was 0.36 μM using 10σ indicating a very high sensitivity. The colorimetric sensor showed good reproducibility and a recovery rate between 92.3% and 102.6%, indicating high accuracy and reliability. The findings of this work confirmed that PVP-NiONPs possess enzyme-like activity and are a promising alternative for the quantitative, on-site detection of ascorbic acid. Full article

(This article belongs to the Special Issue Cutting-Edge Nanozyme Biosensing Strategies for Biomedical and Environmental Applications)

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17 pages, 1460 KB

Open AccessArticle

Rapid Eukaryotic Impedimetric Biosensing of Naproxen and Isoniazid: A Proof-of-Concept for Acute Toxicity Monitoring

by Zala Štukovnik, Nik Perko and Urban Bren

Biosensors 2026, 16(5), 298; https://doi.org/10.3390/bios16050298 - 20 May 2026

Cited by 1 | Viewed by 714

Abstract

This study presents a rapid, eukaryotic impedimetric biosensor that applies the yeast Saccharomyces cerevisiae as a robust, cost-effective biorecognition element for monitoring the acute toxicity of two representative pharmaceuticals, naproxen and isoniazid, in aquatic systems. The biosensor utilizes a previously developed three-electrode system [...] Read more.

This study presents a rapid, eukaryotic impedimetric biosensor that applies the yeast Saccharomyces cerevisiae as a robust, cost-effective biorecognition element for monitoring the acute toxicity of two representative pharmaceuticals, naproxen and isoniazid, in aquatic systems. The biosensor utilizes a previously developed three-electrode system made from type 316 stainless steel. Yeast cells seeded onto these electrodes serve as the biosensing element. By monitoring changes in electrical impedance, the system quantifies the cellular stress induced by pharmaceutical exposure. Electrochemical Impedance Spectroscopy (EIS) revealed a concentration-dependent decrease in both resistance and capacitance, attributed to cell death and subsequent desorption from the working electrode surface. These findings were validated through optical density at 600 nm (OD₆₀₀) growth curve analysis and methylene blue viability staining, which confirmed metabolic inhibition and membrane damage. Results indicate a linear response for naproxen within the 2.5 mM to 20 mM range, with a LOD of 0.509 mM, and for isoniazid within the 10 mM to 100 mM range, with a LOD of 0.684 mM. Naproxen demonstrated a more pronounced cytotoxic effect, with cell viability dropping to 41.08% at 10 mM compared to 68.79% for isoniazid. While conventional analytical methods focus on chemical quantification, this proof-of-concept biosensor provides a rapid toxic/non-toxic signal, offering a biologically relevant tool for real-time monitoring of industrial waste streams and acute environmental contamination. Full article

(This article belongs to the Special Issue Cell-Based Biosensors for Rapid Detection and Monitoring (3rd Edition))

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26 pages, 2208 KB

Open AccessReview

Synthetic Biology-Enabled Biosensing Platforms for Point-of-Care In Vitro Diagnostics: Programmable Modules, Clinical Applications, and Translational Challenges

by Changjie Bao, Honglin Zhang, Lin Jiang, Tianhui Liu, Wei Liu, Qi Qi, Xuejiao Ren, Hongxun Fu and Meiyan Sun

Biosensors 2026, 16(5), 297; https://doi.org/10.3390/bios16050297 - 20 May 2026

Viewed by 1533

Abstract

Synthetic biology is reshaping in vitro diagnostics (IVD) by enabling programmable and modular biosensing elements that can be integrated into point-of-care testing (POCT) platforms. Compared with conventional assays that depend on fixed chemistries and centralized instrumentation, synthetic biology-based systems offer adaptable molecular recognition, [...] Read more.

Synthetic biology is reshaping in vitro diagnostics (IVD) by enabling programmable and modular biosensing elements that can be integrated into point-of-care testing (POCT) platforms. Compared with conventional assays that depend on fixed chemistries and centralized instrumentation, synthetic biology-based systems offer adaptable molecular recognition, tunable signal processing, and flexible readout formats for decentralized diagnostics. In this review, we present synthetic biology-enabled IVD as programmable biosensing platforms organized into four functional layers: molecular recognition, signal transduction and amplification, output generation, and system integration. We discuss four major enabling modules, including cell-free protein synthesis (CFPS) systems, aptamer and riboswitch sensors, CRISPR-Cas diagnostic platforms, and microfluidic integration technologies. We summarize representative clinical applications from 2021 to 2025 in infectious disease detection, cancer biomarker analysis, and drug metabolism/toxicity screening. In addition, we examine practical considerations beyond analytical sensitivity, including matrix tolerance, workflow complexity, manufacturability, quantitative capability, and regulatory readiness. Finally, we highlight future directions for programmable diagnostics, including AI-assisted biosensor design, multimodal readouts, interoperable platform architectures, and real-world clinical validation. Full article

(This article belongs to the Section Biosensors and Healthcare)

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18 pages, 51753 KB

Open AccessArticle

An LSPR-Active AuNP–Silicone Hydrogel Contact Lens for Continuous Ocular Strain Sensing: From Engineering Design to In Vivo Validation

by Yu Tang, Luhua Meng, Yun Liu and Xiang Ma

Biosensors 2026, 16(5), 296; https://doi.org/10.3390/bios16050296 - 20 May 2026

Viewed by 728

Abstract

Continuous intraocular pressure (IOP) monitoring is crucial for glaucoma management. Currently, traditional static IOP measurements often fail to detect circadian fluctuations, leading to a clinical dilemma where “normal IOP” is observed despite persistent visual field deterioration. This study presents a wireless, passive localized [...] Read more.

Continuous intraocular pressure (IOP) monitoring is crucial for glaucoma management. Currently, traditional static IOP measurements often fail to detect circadian fluctuations, leading to a clinical dilemma where “normal IOP” is observed despite persistent visual field deterioration. This study presents a wireless, passive localized surface plasmon resonance (LSPR) sensing platform integrated into flexible silicone hydrogel contact lenses. Gold nanoparticles (AuNPs), synthesized via the sodium citrate reduction method, were incorporated into the lens periphery using a “swelling-induced nano-doping” technique to transduce IOP-induced corneal strain into detectable spectral shifts. Ex vivo porcine eye investigations established a physical mapping model, confirming significant LSPR peak wavelength response trends in correlation with IOP variations (10–50 mmHg) and corneal curvature changes. Subsequent 21-day in vivo rabbit studies demonstrated excellent ocular surface biocompatibility; quantitative histopathological analysis (HE, PAS, and Ki67 staining) revealed no significant adverse alterations in corneal endothelial cell density or conjunctival goblet cell function compared to control groups (p > 0.05). Furthermore, the platform maintained high structural integrity and anterior segment tolerance under transient high-IOP conditions. While currently a proof-of-concept, these results indicate that the LSPR-active hybrid system effectively captures dynamic IOP fluctuation patterns as an optical response to acute interventions, providing a foundational engineering path for next-generation, battery-free wearable diagnostics in personalized glaucoma care without the need for built-in electronics. Full article

(This article belongs to the Special Issue Biophysical Sensors for Biomedical/Health Monitoring Applications (2nd Edition))

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29 pages, 3923 KB

Open AccessArticle

EEG Cross-Subject Taste Classification Method: A Meta-Learning Wavelet Graph Convolutional Neural Network Under Sweet and Bitter Stimuli

by He Wang, Hong Men and Yan Shi

Biosensors 2026, 16(5), 295; https://doi.org/10.3390/bios16050295 - 19 May 2026

Cited by 1 | Viewed by 771

Abstract

Traditional taste evaluation relies heavily on manual sensory analysis, which is highly subjective and inefficient with poor cross-individual generalization, limiting its application in industrial flavor detection. To achieve accurate cross-subject taste recognition, this paper proposes an electroencephalogram (EEG) classification method based on a [...] Read more.

Traditional taste evaluation relies heavily on manual sensory analysis, which is highly subjective and inefficient with poor cross-individual generalization, limiting its application in industrial flavor detection. To achieve accurate cross-subject taste recognition, this paper proposes an electroencephalogram (EEG) classification method based on a meta-learning wavelet graph convolutional neural network (ML-WGCNet) under sweet- and bitter-taste stimuli. Sucrose (sweetness) and quinine (bitterness) were used as stimulation sources, each prepared at six concentration gradients, including a water control. EEG signals were detected from 20 subjects. First, the Morlet wavelet transform was applied to decompose the EEG signals in the time–frequency domain, extracting the maximum and average energy values from five frequency bands as core features. A graph structure was then constructed using electrodes as nodes and Pearson correlation coefficients between electrodes as edge weights. A lightweight graph convolutional neural network (GCN) is employed to model spatial correlations among brain regions. Finally, by integrating a meta-learning framework and adopting leave-one-subject-out cross-validation, the model can rapidly adapt to new subjects. The experimental results show that the proposed method achieves average accuracies of 76.03% and 77.01% in cross-subject classification of sweet and bitter tastes, respectively. The corresponding precision values are 79.94% and 79.53%, the recall values are 75.77% and 78.51%, and the F1-scores are 78.24% and 78.08%, respectively, demonstrating that the proposed model significantly outperforms existing mainstream EEG classification methods. Full article

(This article belongs to the Special Issue Applications of AI in Non-Invasive Biosensing Technologies)

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34 pages, 11276 KB

Open AccessReview

State-of-the-Art Applications of Field-Effect Transistor Biosensors in Exosome Detection: A Comprehensive Review

by Xinyi Sheng, Guo-Jun Zhang and Jie Zhou

Biosensors 2026, 16(5), 294; https://doi.org/10.3390/bios16050294 - 18 May 2026

Viewed by 674

Abstract

Exosomes are a kind of nanoscale extracellular vesicle secreted by almost all cell types and considered promising biomarkers for disease diagnosis since they could carry abundant proteins, nucleic acids, and lipids that reflect parental cell states. However, conventional exosome detection methods suffer from [...] Read more.

Exosomes are a kind of nanoscale extracellular vesicle secreted by almost all cell types and considered promising biomarkers for disease diagnosis since they could carry abundant proteins, nucleic acids, and lipids that reflect parental cell states. However, conventional exosome detection methods suffer from several limitations including insufficient specificity, low throughput, high costs, and inadequate sensitivity for clinical applications. By contrast, field-effect transistor (FET) biosensors are a promising alternative by enabling label-free, real-time, and ultrasensitive detection of exosomes through direct transduction of biorecognition events into electrical signals. This review first introduces the fundamental principles and device structure of FET biosensors, as well as exosome isolation strategies. The recent advances in exosome analysis using FET-based biosensors are then presented, which are categorized into two primary strategies: (1) direct detection of intact exosomes based on surface markers, including tetraspanin proteins (CD9, CD63, CD81, etc.) and disease-specific biomarkers, and (2) detection of exosomal contents including microRNA and protein biomarkers following exosome lysis. Finally, we discuss current challenges of FET-based exosome detection and provide perspectives on future developments. Full article

(This article belongs to the Section Biosensors and Healthcare)

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12 pages, 1000 KB

Open AccessArticle

A Magnetic-Assisted CRISPR-Cas12a Biosensor Incorporating a Y-DNA Probe for Sensitive Detection of Schistosoma japonicum Eggs

by Ting Liu, Haogang Guo, Mengmeng Yu, Jiawei Peng, Liwen Guan, Shuying Xie, Xian Hao and Yifei Yang

Biosensors 2026, 16(5), 293; https://doi.org/10.3390/bios16050293 - 18 May 2026

Viewed by 884

Abstract

Schistosomiasis, caused by Schistosoma species, is notoriously difficult to accurately diagnose with conventional methods. In this study, we present an innovative biosensor that integrates CRISPR–Cas12a technology with nucleic acid aptamers for the highly sensitive detection of Schistosoma japonicum eggs. The biosensor leverages [...] Read more.

Schistosomiasis, caused by Schistosoma species, is notoriously difficult to accurately diagnose with conventional methods. In this study, we present an innovative biosensor that integrates CRISPR–Cas12a technology with nucleic acid aptamers for the highly sensitive detection of Schistosoma japonicum eggs. The biosensor leverages a Y-shaped DNA structure (Y-DNA) that incorporates an aptamer specific to S. japonicum eggs, along with an activator DNA and a segment for immobilization on magnetic nanomaterials. Upon target recognition, the Y-DNA releases the activator, which triggers the collateral cleavage activity of Cas12a, enabling the direct detection of eggs. This system demonstrates remarkable sensitivity, being capable of detecting individual eggs in infected rabbit serum and feces. Moreover, it effectively distinguishes the eggs of S. japonicum from those of other parasitic species. The simplicity, high sensitivity, and rapid detection of our biosensor offer significant potential for improving the diagnosis of schistosomiasis, providing a novel, reliable tool for early detection in clinical settings. Full article

(This article belongs to the Special Issue Nanomaterial-Assisted CRISPR Biosensing for Health Related Detection)

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19 pages, 26178 KB

Open AccessArticle

Angle-Dependent Dip Coating Strategy for Silver Nanostructured Surface Fabrication with Enhanced Fluorescence and Surface-Enhanced Raman Scattering Properties

by Longchao Qi, Kaibo Guo, Xianlong Ning, Yiming Huang and Xun Lu

Biosensors 2026, 16(5), 292; https://doi.org/10.3390/bios16050292 - 16 May 2026

Viewed by 630

Abstract

Noble metal nanostructures based on localized surface plasmon resonance (LSPR) can induce metal-enhanced fluorescence (MEF) and surface-enhanced Raman scattering (SERS), significantly improving trace detection sensitivity for biomedical and chemical analysis. While self-assembly of noble metal nanoparticles offers simplicity and low equipment dependence, achieving [...] Read more.

Noble metal nanostructures based on localized surface plasmon resonance (LSPR) can induce metal-enhanced fluorescence (MEF) and surface-enhanced Raman scattering (SERS), significantly improving trace detection sensitivity for biomedical and chemical analysis. While self-assembly of noble metal nanoparticles offers simplicity and low equipment dependence, achieving large-area, uniform, and controllable nanostructures remains challenging. In this study, angle-dependent dip coating (ADDC) technology was employed to achieve efficient, controllable self-assembly of silver nanoparticles (AgNPs) on glass slides, establishing a fabrication process for MEF/SERS dual-functional substrates. A stable AgNPs-anhydrous ethanol suspension was prepared and extracted from an inclined substrate reservoir using a microfluidic syringe pump, enabling large-area uniform nanostructure assembly. Systematic investigation revealed that substrate inclination angle provides better morphology and fluorescence enhancement control than withdrawal flow rate. The silver nanostructured surface fabricated under a withdrawal flow rate of 16 mL/h and a substrate inclination angle of 30° exhibited a Cy3 detection limit as low as

10^{- 1}

nM, with an enhancement factor ranging from 19.14 to 28.66, as well as an R6G SERS detection limit of

10^{- 10}

M with an enhancement factor of 4.07 ×

10^{8}

. This study confirms that ADDC technology enables simple, efficient, large-area uniform AgNPs self-assembly for superior dual-function enhancement substrates, offering a cost-effective and efficient strategy for highly sensitive trace detection. Full article

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

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12 pages, 2308 KB

Open AccessArticle

High-Precision Detection of Magnetic Nanoparticles in Microfluidic Biosensing Systems

by Dakota Brown, Wendell Manuel, Dan Luu, Tri-Duc Luong, Marienette Morales Vega and Manh-Huong Phan

Biosensors 2026, 16(5), 291; https://doi.org/10.3390/bios16050291 - 16 May 2026

Viewed by 725

Abstract

The low signal-to-noise ratio (SNR) of existing magnetic sensors limits the detection of magnetic nanoparticles (MNPs) in microfluidic biosensing. We present a novel microfluidic coil-based impedance detection system for quantifying magnetic particles, including Fe filings and citrate-coated Fe₃O₄ MNPs, with [...] Read more.

The low signal-to-noise ratio (SNR) of existing magnetic sensors limits the detection of magnetic nanoparticles (MNPs) in microfluidic biosensing. We present a novel microfluidic coil-based impedance detection system for quantifying magnetic particles, including Fe filings and citrate-coated Fe₃O₄ MNPs, with potential applications in magnetically guided biosensing. Unlike conventional approaches that directly measure the magnetic properties of dispersed particles, our method employs an external collector magnet to concentrate particles within a copper coil detector. The accumulated particles alter the coil’s electromagnetic response through changes in the sample’s dielectric properties, producing an amplified impedance signal proportional to sample volume. We evaluated detection performance for 1–10 mg of ferromagnetic Fe filings and citrate-coated Fe₃O₄ MNPs across a broad frequency range. Results show a strong linear correlation between particle mass and impedance change, with SNR values from 25 dB to over 45 dB, demonstrating high sensitivity and precision. Coil sensitivity was further optimized by varying the number of turns (5, 10, and 15), enabling frequency-specific customization. This approach provides a scalable, low-cost platform adaptable to polymer-coated MNPs targeting biological analytes. Full article

(This article belongs to the Special Issue Recent Advances in Microfluidics for Bioanalysis and Diagnostics)

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19 pages, 5443 KB

Open AccessArticle

Impedance Sensing and Characterization of Single-Cell Migration in Channels with Selective Protein Coating

by Xiao Hong and Stella W. Pang

Biosensors 2026, 16(5), 290; https://doi.org/10.3390/bios16050290 - 16 May 2026

Viewed by 719

Abstract

Understanding cell migration is essential not only for fundamental biology but also for the development of targeted disease therapies. Traditional in vitro cell migration assays typically rely on optical microscopy to capture cell movements and subsequent image-based tracking to quantify cell migration characteristics, [...] Read more.

Understanding cell migration is essential not only for fundamental biology but also for the development of targeted disease therapies. Traditional in vitro cell migration assays typically rely on optical microscopy to capture cell movements and subsequent image-based tracking to quantify cell migration characteristics, which often involve substantial experimental workload and analytical complexity. Therefore, there is a need for an automated and streamlined approach to monitor and analyze cell movements. In this work, a microfabricated impedance sensor integrating electrode pairs and selectively protein-coated channels was developed for real-time monitoring of single-cell migration. The optimized electrode dimensions with 10 μm width and 10 μm gap enabled sensitive detection of impedance magnitude increase induced by individual cells. The impedance magnitude changes were correlated with the cell coverage area on electrodes, allowing continuous tracking of single-mouse osteoblast MC3T3 cell movement across the electrode pair. Distinct impedance responses of signal duration and magnitude were observed under different surface coatings, revealing the influence of microenvironmental chemistry on cell motility and adhesion. Furthermore, comparative impedance profiling of MC3T3 and nasopharyngeal epithelial NP460 cells demonstrated that MC3T3 cells produced larger changes in impedance real part and phase due to larger spreading area and larger number of focal adhesions, whereas NP460 cells showed shorter impedance signal change durations, consistent with faster cell migration. These electrical signatures collectively captured intrinsic differences in cell morphology, adhesion, and motility. The developed impedance sensor provides a label-free approach for single-cell migration characterization and can be potentially applied to cell identification. Full article

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

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13 pages, 7405 KB

Open AccessArticle

Glycemic Efficacy and Safety by Using Insulin Degludec and Aspart Guided by a Clinical Decision Support System in Non-Critically Ill Inpatients with Type 2 Diabetes Mellitus

by Felix Aberer, Daniel A. Hochfellner, Petra M. Baumann, Bernhard Höll, Peter Beck, Thomas R. Pieber and Julia K. Mader

Biosensors 2026, 16(5), 289; https://doi.org/10.3390/bios16050289 - 16 May 2026

Viewed by 871

Abstract

Background: Algorithm-based insulin dosing systems are increasingly used in hospitals and have shown the potential to efficiently and safely enable glycemic control. The goal of this study was to evaluate glycemic control using the ultralong-acting basal insulin degludec (IDeg) in combination with insulin [...] Read more.

Background: Algorithm-based insulin dosing systems are increasingly used in hospitals and have shown the potential to efficiently and safely enable glycemic control. The goal of this study was to evaluate glycemic control using the ultralong-acting basal insulin degludec (IDeg) in combination with insulin aspart (IAsp) within an algorithm-driven electronic clinical decision support system (cDSS) in inpatients with type 2 diabetes (T2D). Methods: In this non-controlled single-arm pilot study, an electronic, algorithm-based cDSS was applied for the management of insulin treatment in an internal general ward. Thirty hospitalized patients with T2D (18 female, age 74.1 ± 10.9 years, HbA1c 72.4 ± 22.3 mmol/mol, BMI 28.6 ± 5.6 kg/m², diabetes duration 13.2 ± 11.6 years, creatinine 1.5 ± 1.2 mg/dL, length of hospital stay 9.1 ± 4.0 days) were included in the study. Capillary blood glucose (BG) was evaluated four times daily using a point-of-care device integrated into the hospital information system. In addition, all participants received a blinded continuous glucose monitoring (CGM; Abbott Freestyle Libre Pro) system. The primary endpoint was defined as the percentage of BG measurements within the target range of 3.9–7.8 mmol/L. Results: Overall, 722 BG values and 17,242 CGM data points were available. Of those, 52.2% and 55.0% were in the specified target area (3.9–7.8 mmol/L), respectively. Mean BG prior to study start was 11.9 ± 4.4 mmol/L and improved to 7.5 ± 1.9 mmol/L and 7.4 ± 1.4 mmol/L after 6 and 10 days of treatment. BG < 3.9, <3.0 and <2.2 mmol/L was 1.25%, 0.28% and 0%, respectively. Adherence to the total daily insulin dose suggested by the cDSS was 94.2%, and 99.5% of all basal and 85.3% of all bolus insulin suggestions were accepted by the nurses in charge. Basal-bolus therapy using the cDSS covered 85% of the participants’ total hospital stay. Conclusions: Glycemic control using IDeg within an algorithm-driven cDSS could effectively and safely be achieved in the hospital and was highly accepted. Full article

(This article belongs to the Special Issue Wearable Biosensors and Health Monitoring)

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17 pages, 1370 KB

Open AccessReview

Application of Rapid Detection Technology for the Determination of γ-Hydroxybutyric Acid

by Nan Li, Xingliang Liu, Boyuan Shi, Chunhui Song, Teng Zhang, Xin Yan, Yingying Li, Xinyi Li and Jun Ma

Biosensors 2026, 16(5), 288; https://doi.org/10.3390/bios16050288 - 15 May 2026

Cited by 1 | Viewed by 924

Abstract

The abuse of γ-hydroxybutyric acid (GHB) and its precursors, γ-butyrolactone (GBL) and 1,4-butanediol (1,4-BD), has increased in recent years, with these substances frequently being illicitly added to beverages. GHB is colorless and odorless and exhibits anesthetic and hypnotic psychoactive effects, which are often [...] Read more.

The abuse of γ-hydroxybutyric acid (GHB) and its precursors, γ-butyrolactone (GBL) and 1,4-butanediol (1,4-BD), has increased in recent years, with these substances frequently being illicitly added to beverages. GHB is colorless and odorless and exhibits anesthetic and hypnotic psychoactive effects, which are often exploited in drug-facilitated sexual assault, posing a significant public safety concern. Chromatography–tandem mass spectrometry is a conventional analytical approach for narcotic drug determination due to its high sensitivity and accuracy; however, its large instrumentation footprint and high operational cost limit its suitability for on-site rapid screening. In response to the growing demand for field-deployable analytical tools, rapid detection technologies for GHB have progressively evolved. This review summarizes and compares the advantages and limitations of current rapid detection methods for GHB and discusses their potential future developmental trends, with the aim of providing a reference for researchers and relevant authorities. Full article

(This article belongs to the Special Issue Microfluidics for Sample Pretreatment)

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27 pages, 2148 KB

Open AccessReview

Wearable Biosensors for Continuous Monitoring of Chronic Kidney Disease: Materials, Biofluids, and Digital Health Integration

by Anupamaa Sivasubramanian, Shankara Narayanan and Gymama Slaughter

Biosensors 2026, 16(5), 287; https://doi.org/10.3390/bios16050287 - 15 May 2026

Cited by 2 | Viewed by 1505

Abstract

Chronic kidney disease (CKD) is a progressive and irreversible disorder affecting over 850 million individuals globally and is associated with significant morbidity, mortality, and healthcare burden. Conventional diagnostic approaches rely on intermittent laboratory measurements, including serum creatinine, estimated glomerular filtration rate (eGFR), and [...] Read more.

Chronic kidney disease (CKD) is a progressive and irreversible disorder affecting over 850 million individuals globally and is associated with significant morbidity, mortality, and healthcare burden. Conventional diagnostic approaches rely on intermittent laboratory measurements, including serum creatinine, estimated glomerular filtration rate (eGFR), and urinary albumin, which provide limited temporal resolution and fail to capture dynamic physiological changes. Recent advances in wearable biosensing technologies offer new opportunities for continuous, non-invasive monitoring of biochemical and physiological markers relevant to renal function. This review provides a comprehensive analysis of wearable biosensors for CKD monitoring, focusing on sensing mechanisms (electrochemical, optical, and field-effect transistor), biofluid interfaces (sweat, interstitial fluid, and saliva), and materials engineering strategies enabling flexible, high-performance devices. Emphasis is placed on biofluid transport dynamics, analytical performance across sampling matrices, and system-level integration with wireless communication and digital health platforms. Key challenges limiting clinical translation, including biofouling, enzymatic instability, and variability in biofluid composition, are examined—alongside emerging solutions such as antifouling interfaces, synthetic recognition elements, and multimodal sensing architectures. Finally, regulatory pathways and the role of artificial intelligence in digital nephrology are discussed. This review highlights the potential of wearable biosensors to transform CKD management through continuous monitoring, early detection, and personalized therapeutic intervention. Full article

(This article belongs to the Special Issue AI/ML-Enabled Biosensing: Shaping the Future of Disease Detection)

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20 pages, 3878 KB

Open AccessArticle

Surface-Modified Extrinsic Semi-Distributed Interferometers for Fiber-Optic Refractive Index Detection and Biosensing

by Albina Abdossova, Toheeb Olalekan Oladejo, Sabira Seipetdenova, Marzhan Nurlankyzy, Aigerim Omirzakova, Aidana Bissen, Aliya Bekmurzayeva, Carlo Molardi, Cevat Erisken, Wilfried Blanc and Daniele Tosi

Biosensors 2026, 16(5), 286; https://doi.org/10.3390/bios16050286 - 15 May 2026

Viewed by 1066

Abstract

A semi-distributed interferometer is a low-reflectivity device with refractive index sensing capability, exploiting the random reflectivity of a nanoparticle-doped fiber to form a weak distributed cavity. In this work, we extend this concept to an extrinsic semi-distributed interferometer (ESDI), using an overlay made [...] Read more.

A semi-distributed interferometer is a low-reflectivity device with refractive index sensing capability, exploiting the random reflectivity of a nanoparticle-doped fiber to form a weak distributed cavity. In this work, we extend this concept to an extrinsic semi-distributed interferometer (ESDI), using an overlay made of polydimethylsiloxane (PDMS) around the fiber tip; this structure can then be surface-modified using a thin metallic film or a nanoparticle coating. We report gold-sputtered and gold-nanoparticle-coated ESDI structures for refractive index sensing capability, with the latter achieving superior performances with an average sensitivity of 62.8 dB/RIU (refractive index units) with resolution of 3.9 × 10⁻⁵ RIU over the range of 1.34790–1.35981. We also report a possible biological application using a biofunctionalized version of this probe for the detection of VEGF (vascular endothelial growth factor); the gold-sputtered probe achieves the highest sensitivity, 0.0565 dB for each 10× concentration increase, with 355 fM detection limit. Full article

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

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28 pages, 14925 KB

Open AccessArticle

State-Referenced Truncated SVD for Dynamic Microwave Monitoring of Intracranial Hemorrhage

by Zekun Zhang, Heng Liu, Ruide Li, Huiyuan Zhu, Fan Li, Shujun Ni, Aojun Liu and Yao Zhai

Biosensors 2026, 16(5), 285; https://doi.org/10.3390/bios16050285 - 14 May 2026

Viewed by 959

Abstract

Microwave imaging is a promising non-ionizing technique for bedside follow-up of intracranial hemorrhage, but dynamic monitoring remains challenging under limited multistatic sampling because weak inter-frame changes can be obscured by measurement variability, model mismatch, and the high cost of frame-by-frame nonlinear inversion. To [...] Read more.

Microwave imaging is a promising non-ionizing technique for bedside follow-up of intracranial hemorrhage, but dynamic monitoring remains challenging under limited multistatic sampling because weak inter-frame changes can be obscured by measurement variability, model mismatch, and the high cost of frame-by-frame nonlinear inversion. To address this problem, this paper proposes a state-referenced truncated singular-value decomposition (SR-TSVD) framework for dynamic microwave monitoring of hemorrhagic evolution. The method maintains an internal gate state and reconstructs only the state-referenced increment at each monitoring instant. A row-whitened TSVD inversion is introduced to reduce channel dominance effects and improve robustness to route-dependent imbalance, while a residual-driven gate-refresh mechanism updates the internal state only when the current linearization background becomes insufficiently accurate. The proposed method was validated through two-dimensional numerical experiments and hardware phantom measurements. The numerical study examined different lesion evolution scenarios and analyzed the effects of antenna count, frequency diversity, and measurement noise. The hardware study showed that the method preserves the main dynamic evolution in a real measurement system and remains more stable than baseline linear methods under sparse array conditions. These results indicate that SR-TSVD provides an effective and computationally practical framework for repeated bedside microwave monitoring of intracranial hemorrhage. Full article

(This article belongs to the Special Issue Biosensors for Physiological Signal Monitoring)

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19 pages, 2514 KB

Open AccessArticle

Spatially Resolved Biosensing of Localized Dopamine Release via Its Electropolymerization Using Plasmonic Electrochemical Microscopy

by Christian Martinez, Samuel Groysman, Madison Ngo and Yixian Wang

Biosensors 2026, 16(5), 284; https://doi.org/10.3390/bios16050284 - 14 May 2026

Viewed by 720

Abstract

The precise spatiotemporal monitoring of dopamine is critical for understanding neurotransmission and neurodegenerative pathologies. While traditional electrochemical methods offer excellent temporal resolution, they lack the spatial resolution required to map network-wide dynamic events. To address this, we adapted a wide-field plasmonic electrochemical microscopy [...] Read more.

The precise spatiotemporal monitoring of dopamine is critical for understanding neurotransmission and neurodegenerative pathologies. While traditional electrochemical methods offer excellent temporal resolution, they lack the spatial resolution required to map network-wide dynamic events. To address this, we adapted a wide-field plasmonic electrochemical microscopy (PEM) platform to spatially image localized electrochemical reactions. Specifically, we leveraged the anodic electropolymerization of dopamine into a surface-confined polydopamine nanofilm to enable label-free, pixel-level optical quantification. Bulk solution testing demonstrated highly uniform sensor sensitivity, yielding an estimated single-pixel limit of detection of 14 pM. Furthermore, utilizing a custom injection system, we successfully imaged the real-time localized delivery of micromolar dopamine concentrations and demonstrated qualitative responsiveness of the integrated optical signal to delivered dopamine as a proof-of-concept for the platform. The platform functions as a spatially resolved mass integrator while simultaneously decoupling this chemical signal from transient hydrodynamic mechanical deformations caused by dopamine injection flow. Ultimately, this platform establishes the fundamental methodology required for future high-throughput spatial monitoring of complex neurotransmitter release dynamics across cellular networks. Full article

(This article belongs to the Special Issue Functional Nanomaterials for Advanced Biosensing: From Molecular Design to Real-World Applications)

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21 pages, 1467 KB

Open AccessReview

State-of-the-Art and Next Generation Intra-Articular Implantable Biosensors for Osteoarthritis: From Analytical Limits to Operational Stability

by Abdullateef Gbolahan Olayiwola, Albina Abdossova, Daniele Tosi, Gorka Orive, Zhe Liu and Cevat Erisken

Biosensors 2026, 16(5), 283; https://doi.org/10.3390/bios16050283 - 14 May 2026

Viewed by 806

Abstract

Osteoarthritis (OA) and osteochondral degeneration present a significant clinical burden characterized by the complex interplay of extracellular matrix degradation and chronic inflammation. While biochemical profiling has matured, a critical translational gap remains in transitioning from benchtop assays to systems capable of continuous, intra-articular [...] Read more.

Osteoarthritis (OA) and osteochondral degeneration present a significant clinical burden characterized by the complex interplay of extracellular matrix degradation and chronic inflammation. While biochemical profiling has matured, a critical translational gap remains in transitioning from benchtop assays to systems capable of continuous, intra-articular monitoring. This review provides a comprehensive synthesis of experimentally validated biosensing technologies, including optical, electrochemical, and piezoelectric Quartz Crystal Microbalance (QCM) platforms, evaluated through the lens of sensing architecture, biomarker specificity, and matrix compatibility. Our analysis reveals that while optical sensors offer superior sensitivity, electrochemical platforms show the greatest promise for miniaturized, implantable integration. However, a pivot in the field is identified: the primary bottleneck has shifted from analytical detection limits to operational stability within the hostile synovial environment. Current research is largely restricted to single-analyte detection in simplified media, failing to address the multifactorial nature of OA. We propose that the next generation of osteochondral diagnostics must prioritize multiplexed arrays, mechanically compliant architectures, and machine-learning-assisted signal processing. By bridging these engineering frontiers, biosensors will evolve from passive diagnostic tools into intelligent, personalized platforms for real-time disease management. Full article

(This article belongs to the Special Issue Biosensing Technologies in Medical Diagnosis—2nd Edition)

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12 pages, 2553 KB

Open AccessArticle

Label-Free Quantification of Bilirubin Using a Refractive Index-Insensitive Nanolaminate SERS Substrate

by Jiwon Yun, Inyoung Kim and Wonil Nam

Biosensors 2026, 16(5), 282; https://doi.org/10.3390/bios16050282 - 14 May 2026

Viewed by 718

Abstract

Bilirubin is an important biomarker, where a small unbound fraction dissociated from albumin can cross the blood–brain barrier and induce neurotoxicity, such as kernicterus, at low nanomolar levels. Accurate detection of this low-level fraction remains challenging. Surface-enhanced Raman spectroscopy (SERS) enables label-free molecular [...] Read more.

Bilirubin is an important biomarker, where a small unbound fraction dissociated from albumin can cross the blood–brain barrier and induce neurotoxicity, such as kernicterus, at low nanomolar levels. Accurate detection of this low-level fraction remains challenging. Surface-enhanced Raman spectroscopy (SERS) enables label-free molecular detection; however, variations in the local refractive index (RI) at plasmonic hotspots can detune the resonance from the excitation wavelength, leading to signal fluctuations and limited quantitative reliability. Here, we present a multi-resonant nanolaminate SERS substrate designed to achieve RI-insensitive and robust signal enhancement. The vertically stacked metal–insulator–metal architecture provides broadband spectral overlap with both excitation and Raman scattering under dielectric loading, maintaining consistent enhancement across varying RI conditions. We demonstrate label-free bilirubin detection with a highly linear response over 10⁻⁹ to 10⁻⁴ M, achieving an R² value of 0.99. Compared with previously reported bilirubin SERS substrates relying mainly on single-resonant plasmonic enhancement, this RI-insensitive design offers improved quantitative reliability under dielectric environmental changes. These results highlight the importance of RI-insensitive SERS design for reliable quantification and provide a general strategy for robust SERS-based biosensing. Full article

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

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30 pages, 1576 KB

Open AccessReview

Microfluidic and MEMS-Based Biosensing Platforms for Fungal Respiratory Infections in Immunocompromised Patients: Toward Rapid, Specific, and Minimally Invasive Diagnosis

by Vasiliki E. Georgakopoulou and Vassiliki C. Pitiriga

Biosensors 2026, 16(5), 281; https://doi.org/10.3390/bios16050281 - 12 May 2026

Viewed by 1298

Abstract

Invasive fungal respiratory infections (IFRIs) remain a major cause of morbidity and mortality among immunocompromised patients, yet diagnosis continues to be hindered by nonspecific clinical features, limited sample accessibility, and the poor sensitivity or specificity of conventional tests. Microfluidic and microelectromechanical systems (MEMS)-based [...] Read more.

Invasive fungal respiratory infections (IFRIs) remain a major cause of morbidity and mortality among immunocompromised patients, yet diagnosis continues to be hindered by nonspecific clinical features, limited sample accessibility, and the poor sensitivity or specificity of conventional tests. Microfluidic and microelectromechanical systems (MEMS)-based biosensing platforms have emerged as promising alternatives, enabling rapid, minimally invasive, and highly specific detection of fungal pathogens and host responses. Microfluidic nucleic acid and antigen assays allow on-chip amplification and immunodetection with reduced sample volumes and turnaround times, while CRISPR-enhanced systems further improve analytical sensitivity. Parallel advances in host response profiling—including transcriptomic, proteomic, and cytokine-based signatures—have demonstrated feasibility for integration into lab-on-a-chip platforms. MEMS-based technologies extend this potential by facilitating real-time analysis of exhaled volatile organic compounds, mechanical biosensing of fungal DNA and antigens, and in situ monitoring of device-associated biofilms. Translational studies highlight potential applications across intensive care, hematology–oncology, and transplant settings, as well as in outpatient monitoring of high-risk populations. However, several challenges remain, including limited multicenter validation, matrix-related biofouling effects, and a lack of standardization in fungal biomarker panels. Future directions include AI-driven interpretation of multianalyte data, multiplexed integration of host and pathogen markers, and development of fully cartridge-based systems for near-patient deployment. Collectively, these innovations may shift fungal diagnostics toward earlier, more precise, and patient-tailored interventions, improving outcomes in vulnerable populations. Full article

(This article belongs to the Special Issue Advanced Microfluidic Devices and MEMS in Biosensing Applications)

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27 pages, 4867 KB

Open AccessReview

Insights into Sensing and Biomedical Domains Using Multi-Synthetic Covalent Organic Frameworks

by Hassan Imam Rizvi, Yuchen Qiao, Shilpa Dabas, Peng Ren and Xuemei Yang

Biosensors 2026, 16(5), 280; https://doi.org/10.3390/bios16050280 - 11 May 2026

Viewed by 1555

Abstract

Covalent organic frameworks (COFs) are one of the most important crystalline structures, having high porosity, and are mostly composed of lighter elements, such as H, C, N, O, etc., with covalent bonds between them. They are chemically synthesized in a repetitive arrangement and [...] Read more.

Covalent organic frameworks (COFs) are one of the most important crystalline structures, having high porosity, and are mostly composed of lighter elements, such as H, C, N, O, etc., with covalent bonds between them. They are chemically synthesized in a repetitive arrangement and create a highly effective porous surface area that plays a fundamental role in various applications including sensing and biomedical applications. This study offers an overview of COFs in sensing and biomedical applications and provides a detailed overview of various synthesis procedures of COFs. Next, we explore their innovative sensing performances in the cases of various gases, ions and metals. Finally, it is emphasized that the major biomedical applications of COFs have been addressed regarding diseases and treatment strategies. Overall, this review offers an overview of COFs’ capabilities and promising behaviors in enhancing and revolutionizing sensing and biomedical technologies. Full article

(This article belongs to the Special Issue Advances in Biosensors Based on Framework Materials)

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12 pages, 6932 KB

Open AccessArticle

DNA Electrochemical Sensor Based on Exonuclease III-Assisted Cycling Signal Amplification for Ultrasensitive Detection of Genetically Modified Soybean

by Lidan Niu, Siyu Huang, Jinmei Zhao, Wenjing Yang, Zhengnan Li, Siqi Niu, Jianchun Yang, Shiqi Chen and Qihui Wang

Biosensors 2026, 16(5), 279; https://doi.org/10.3390/bios16050279 - 11 May 2026

Viewed by 816

Abstract

The safety of genetically modified crops, particularly the commercial cultivation of glyphosate-resistant genetically modified soybeans, has given rise to significant public concern. Consequently, there is an urgent need to develop efficient and precise methods for detecting genetically modified components. The present study constructed [...] Read more.

The safety of genetically modified crops, particularly the commercial cultivation of glyphosate-resistant genetically modified soybeans, has given rise to significant public concern. Consequently, there is an urgent need to develop efficient and precise methods for detecting genetically modified components. The present study constructed a novel electrochemical biosensor based on nucleic acid exonuclease III (Exo III)-assisted cyclic signal amplification and hairpin probe recognition for the highly sensitive and specific detection of the CP4-EPSPS gene in genetically modified soybeans. The sensor achieves exponential signal amplification by triggering Exo III to cyclically cleave the hairpin probe (H1) upon target DNA binding. Subsequent to this, the released DNA fragments hybridize with the methylene blue-labeled signal probe (HS-MB) that has been immobilized on the electrode surface. This process induces conformational changes and a decrease in the current signal, thereby enabling quantitative analysis of the target gene. The experimental phase of the study successfully validated the sensor’s mechanism and systematically optimized key parameters such as Exo III concentration and reaction time. In optimal conditions, the sensor demonstrated excellent linearity with target DNA concentrations ranging from 100 fM to 10 nM, achieving a detection limit as low as 0.1072 pM. Furthermore, it exhibited remarkable repeatability and stability. This study provides an analytical tool with broad application prospects for the rapid and precise detection of genetically modified crops. Full article

(This article belongs to the Special Issue Emerging Materials for Biosensing in Nano/Microfluidics)

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17 pages, 3227 KB

Open AccessArticle

Systematic Benchmarking of Spectral Demodulation Methods for Ball Resonator and Hybrid FPI–Ball Resonator Sensors for Multiparameter Physiological Monitoring

by Natsnet Bereket Tecle and M. Fátima Domingues

Biosensors 2026, 16(5), 278; https://doi.org/10.3390/bios16050278 - 11 May 2026

Viewed by 822

Abstract

Ball resonator optical fiber sensors (OFSs) can offer multiparameter sensing capability, but their non-periodic and low-finesse reflection spectra make conventional spectral demodulation unreliable. This work proposes two sensor configurations: (i) a ball resonator and (ii) a hybrid sensor integrating a Fabry–Pérot interferometer (FPI) [...] Read more.

Ball resonator optical fiber sensors (OFSs) can offer multiparameter sensing capability, but their non-periodic and low-finesse reflection spectra make conventional spectral demodulation unreliable. This work proposes two sensor configurations: (i) a ball resonator and (ii) a hybrid sensor integrating a Fabry–Pérot interferometer (FPI) with a ball resonator, and compares their performance for multiparameter physiological monitoring using the Karhunen–Loève transform (KLT). The sensors were evaluated for glucose concentration (0–3 mg/mL), temperature (20–55 °C), and pH (3–9) monitoring. The ball resonator sensor, paired with KLT, achieved high linearity across all measurands (R² = 0.989, 0.919, and 0.838 in response to glucose, temperature, and pH, respectively). The hybrid sensor exhibited a higher glucose sensitivity (6.15 a.u./(mg/mL)) compared to the ball resonator (3.77 a.u./(mg/mL)), resulting in limits of detection (LODs) of 2.53 mM and 4.19 mM, respectively. In contrast, the ball resonator sensor demonstrated better sensitivity for temperature and pH sensing. Furthermore, we present a comprehensive benchmarking framework of seven spectral demodulation methods for OFSs. The results demonstrated that KLT consistently provides robust demodulation performance and highlighted the potential of KLT for multiparameter physiological sensing applications. Full article

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

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19 pages, 4047 KB

Open AccessArticle

Laser-Scribed Graphene on PDMS for Flexible Wearable Sweat Biosensors with Multiplexed Sensing Capability

by Aida Rakhimbekova, Lavita Nuraviana Rizalputri, Aris Konstantinidis, Saptami Suresh Shetty and Khaled Nabil Salama

Biosensors 2026, 16(5), 277; https://doi.org/10.3390/bios16050277 - 11 May 2026

Viewed by 1062

Abstract

Sweat is a valuable biofluid for non-invasive health monitoring, as it contains electrolytes, metabolites, and organic compounds that can correlate with blood levels, making it highly attractive for wearable sensing. Building on advances in low-cost, portable electrochemical sensors, sweat analysis enables tracking of [...] Read more.

Sweat is a valuable biofluid for non-invasive health monitoring, as it contains electrolytes, metabolites, and organic compounds that can correlate with blood levels, making it highly attractive for wearable sensing. Building on advances in low-cost, portable electrochemical sensors, sweat analysis enables tracking of hydration status, metabolic stress, and energy availability via key markers such as sodium, potassium, lactate, and glucose. In the sports context, such wearable platforms can support performance optimization and recovery by assessing fluid loss and electrolyte balance in real time. Here, a multiplexed wearable sweat patch is developed to simultaneously monitor temperature, pH, ammonium, sodium, and sweat rate. The integrated platform demonstrates sensitivities of 10.1 mV/ln[NH₄⁺], 9.1 mV/ln[K⁺], 1.11 mV/ln[Na⁺], 14 mV/pH, 0.19% °C⁻¹, and approximately −1.0 mA (mL/min)⁻¹ for sweat rate, with stable signals and linear calibration responses over relevant physiological ranges. The sensor is implemented on a lightweight, biocompatible laser-scribed graphene on a PDMS substrate suitable for prolonged skin contact and mechanical deformation. In addition, a custom PDMS adhesive patch with optimized suction-cup microstructures is engineered to improve skin adhesion under both dry and wet conditions. Finally, the design of the platform was inspired by an adaptive cycling marathon across Saudi Arabia, where an earlier prototype of a wearable patch was deployed for real-time monitoring during a 30-day campaign. Full article

(This article belongs to the Special Issue Wearable Sensors and Biosensors for Physiological Signals Measurement)

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17 pages, 3533 KB

Open AccessArticle

A Comparison of Cost-Effective Sensors for a Fluorescence-Based Detection System Used in Biodiagnostic Devices

by Rebecca Vornweg, Christian Decool, Moritz Hemmer, Bastian Stollfuss, Thomas Guenther, Ann-Kathrin Löffler, Roland E. Kontermann and André Zimmermann

Biosensors 2026, 16(5), 276; https://doi.org/10.3390/bios16050276 - 11 May 2026

Viewed by 3920

Abstract

Cost-effective, fluorescence-based biodiagnostic devices have the potential to expand point-of-care (POC) testing in resource-limited settings, thereby creating new opportunities for accessible and decentralised diagnostics. The objective of this study is to investigate the performance of a newly designed and simplified system that uses [...] Read more.

Cost-effective, fluorescence-based biodiagnostic devices have the potential to expand point-of-care (POC) testing in resource-limited settings, thereby creating new opportunities for accessible and decentralised diagnostics. The objective of this study is to investigate the performance of a newly designed and simplified system that uses several cost-effective sensors for use in a fluorescence-based biodiagnostic setup. A collecting setup that includes an elliptical mirror to focus emitted fluorescence onto the semiconductor sensors was designed for an intensity-based readout. The readout was realised by various photodiodes, photoresistors, phototransistors and one multi-pixel photon counter (MPPC). Over a range of fluorophore concentrations using serial dilutions of Rhodamine B (RhB), the limit of detection (LOD) and limit of quantification (LOQ) at system level were evaluated. With the exception of the photodiodes, the system demonstrated promising performance with all sensors. The system using the photoresistors achieved the lowest LOD but showed limited repeatability, while the system using the MPPC and phototransistors exhibited high repeatability. A proof-of-concept demonstrated the feasibility of a photoresistor-based configuration by using a sandwich immunoassay for the detection of the antigen Human Epidermal growth factor Receptor 2 (HER2) (100 nM). While this study has not yet encompassed the full spectrum of clinically relevant concentrations, it has yielded valuable insights to enable further enhancements, without the necessity for highly specialised or costly equipment. The limitations and necessary improvements for further developments are discussed. Full article

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

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27 pages, 3921 KB

Open AccessArticle

RT-AFNet: A Hybrid ResNet-Transformer Architecture with Multi-Scale Fusion for Atrial Fibrillation Detection

by Xinyu Hu, Qingqing Duan, Yuwei Zhang, Caiyun Ma, Chang Yan and Chengyu Liu

Biosensors 2026, 16(5), 275; https://doi.org/10.3390/bios16050275 - 9 May 2026

Viewed by 970

Abstract

Atrial fibrillation (AF) is a prevalent cardiac arrhythmia associated with an elevated risk of severe complications, including stroke and heart failure. Due to its paroxysmal nature and the inherent complexity of electrocardiogram (ECG) signals, developing highly accurate and robust automated detection methods remains [...] Read more.

Atrial fibrillation (AF) is a prevalent cardiac arrhythmia associated with an elevated risk of severe complications, including stroke and heart failure. Due to its paroxysmal nature and the inherent complexity of electrocardiogram (ECG) signals, developing highly accurate and robust automated detection methods remains a critical challenge. To address the limitations of existing models in simultaneously capturing local morphological anomalies and long-range temporal dependencies, we proposed RT-AFNet, a novel hybrid ResNet-Transformer architecture. Specifically, RT-AFNet integrated the robust local feature extraction capabilities of a Residual Neural Network (ResNet) backbone with the global temporal modeling power of a lightweight self-attention mechanism. Furthermore, a multi-scale feature fusion strategy was introduced to optimize feature representation. The proposed RT-AFNet model was evaluated on three public AF databases: the China Physiological Signal Challenge 2018 (CPSC2018), the PhysioNet/Computing in Cardiology Challenge 2017 (CinC2017), and the MIT-BIH Atrial Fibrillation Database (MIT-BIH AF). The proposed model achieved F1 scores of 99.76%, 97.47%, and 96.20%, along with area under the curve (AUC) values of 99.97%, 98.98%, and 98.28% on the three datasets, respectively. These results demonstrate that the proposed architecture exhibits excellent generalization ability and stability across different databases, providing a robust and reliable deep learning solution for automated AF screening. Full article

(This article belongs to the Special Issue Biosensors for Disease Analysis)

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14 pages, 1201 KB

Open AccessArticle

Ultrasensitive Label-Free Detection of Free Thyroxine (T4) in Physiological Ranges Using Aptamer-Functionalized Silicon Nanowire Field Effect Transistors

by Stephanie Klinghammer, Wiana Butko, Alexandra Parichenko, Gylxhane Kastrati, Abdallh Herbawi, Leif Riemenschneider and Gianaurelio Cuniberti

Biosensors 2026, 16(5), 274; https://doi.org/10.3390/bios16050274 - 9 May 2026

Viewed by 1501

Abstract

Thyroxine (T4) is a key hormone regulating metabolic, cardiovascular, and neurodevelopmental processes, yet its clinical quantification still relies on centralized immunoassays that limit rapid or point-of-care monitoring. Here, we present a label-free biosensing platform based on silicon nanowire field-effect transistors (SiNW-FETs) functionalized with [...] Read more.

Thyroxine (T4) is a key hormone regulating metabolic, cardiovascular, and neurodevelopmental processes, yet its clinical quantification still relies on centralized immunoassays that limit rapid or point-of-care monitoring. Here, we present a label-free biosensing platform based on silicon nanowire field-effect transistors (SiNW-FETs) functionalized with a T4-selective DNA aptamer via a 3-Triethoxysilyl propylsuccinic Anhydride (TESPSA)-mediated silanization approach, enabling a streamlined two-step modification for oriented immobilization. The biosensor achieves robust real-time detection of T4 across the physiological concentration range (5–30 pM), with a limit of detection of ~5 pM and a strong linear correlation between drain current and analyte concentration (R² = 0.9931). Specificity is confirmed using non-functionalized devices and estradiol as a non-target control. All measurements were performed in undiluted phosphate-buffered saline, representing a physiologically relevant ionic environment and demonstrating stable sensor performance under realistic buffer conditions. The dose–response behavior follows a Hill model, allowing extraction of binding parameters and confirming that the electrical signal originates from specific aptamer–target interactions. These results demonstrate that aptamer-functionalized SiNW-FETs provide a highly sensitive, selective, and miniaturizable platform for quantitative thyroid hormone monitoring, with strong potential for future point-of-care applications. Full article

(This article belongs to the Special Issue Multidimensional Nanomaterial-Based Biosensors for Environmental and Healthcare Monitoring)

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16 pages, 14520 KB

Open AccessArticle

Tunable Particle Separation in a Straight Microchannel via Symmetrical Viscoelastic Sheath Flows

by Tianyuan Zhou, Qi Cui, Guizhong Tian, Jing Xia, Ping Liu, Yoichiroh Hosokawa, Yaxiaer Yalikun, Pan Wang, Shilun Feng and Tianlong Zhang

Biosensors 2026, 16(5), 273; https://doi.org/10.3390/bios16050273 - 8 May 2026

Viewed by 1132

Abstract

In this study, we present a novel microfluidic platform for tunable size-based particle separation within a straight microchannel using symmetrical viscoelastic sheath flows. The device incorporates two pairs of symmetrical microchannels for sheath fluid injection: the first pair facilitates particle focusing and separation, [...] Read more.

In this study, we present a novel microfluidic platform for tunable size-based particle separation within a straight microchannel using symmetrical viscoelastic sheath flows. The device incorporates two pairs of symmetrical microchannels for sheath fluid injection: the first pair facilitates particle focusing and separation, while the second pair enables dynamic regulation of the separation distance between particle streams. Experimental results demonstrate that a 50 ppm polyethylene oxide (PEO) solution focuses 1 μm polystyrene particles toward the channel centerline via elastic forces, whereas 5 μm particles migrate toward the channel sidewalls under dominant inertial forces, effectively overcoming the elastic effects. The interplay between inertial and elastic forces thus achieves size-dependent particle separation. Furthermore, by adjusting the flow rate of the PEO sheath in the second pair of microchannels, the separation distance between the two particle populations can be modulated in real time. Higher PEO concentrations (500 and 1000 ppm) exhibit enhanced capabilities to deflect particle flow streams. By contrast, the lower PEO concentrations like 50, 100 and 200 ppm are more versatile in adjusting the separation distance. The biological applicability of this platform is further demonstrated through the tunable separation of Escherichia coli (E. coli) and Chlorella vulgaris (C. vulgaris). This microfluidic device demonstrates significant potential for downstream particle processing applications, including real-time particle detection and targeted drug delivery. Full article

(This article belongs to the Special Issue Design and Application of Microfluidic Biosensors in Biomedicine—2nd Edition)

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20 pages, 3228 KB

Open AccessArticle

Low-Effort Respiratory Function Estimation with a Soft Wearable Digital Spirometry Patch

by Faheem A. Karim, Ahmed Tariq, Christopher B. Fitzpatrick, Lauren Zhou, Mayte Suárez-Fariñas, Helena Schotland, Linda Rogers, Yoon Jae Lee, Woon-Hong Yeo and Yun Soung Kim

Biosensors 2026, 16(5), 272; https://doi.org/10.3390/bios16050272 - 8 May 2026

Viewed by 2760

Abstract

Spirometry is widely regarded as the clinical gold standard for quantifying lung function. It plays a central role in the diagnosis and management of cardiopulmonary disorders, including asthma and chronic obstructive pulmonary disease (COPD). However, the procedure relies on a forceful and often [...] Read more.

Spirometry is widely regarded as the clinical gold standard for quantifying lung function. It plays a central role in the diagnosis and management of cardiopulmonary disorders, including asthma and chronic obstructive pulmonary disease (COPD). However, the procedure relies on a forceful and often stressful expiratory maneuver that may cause patient discomfort and require substantial effort, frequently necessitating active coaching and trained personnel to ensure reproducible measurements. In this paper, we present the Digital Spirometry Patch (DSP), a soft, flexible, wearable patch capable of estimating lung function parameters by utilizing low-effort breathing maneuvers. Eighteen participants performed low-effort and forceful breathing maneuvers while wearing the DSP to collect tracheal sound and chest movement signals for spirometric parameter estimation using elastic net and simple linear regression. Using leave-one-subject-out cross-validation, the elastic net models achieved RMSEs of 0.668 L, 0.224 L, and 0.428 L/s for FVC, FEV₁, and PEF, respectively, using low-effort breathing maneuvers, and 0.499 L, 0.304 L, and 0.891 L/s using forceful exhalation maneuvers. These results demonstrate the potential of the DSP as a wearable, low-effort alternative for estimating lung function outside of conventional spirometry settings. Full article

(This article belongs to the Section Wearable Biosensors)

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