Biosensors

25 pages, 2285 KB

Open AccessArticle

Rationally Designed Molecularly Imprinted Polymer Electrochemical Biosensor with Graphene Oxide Interface for Selective Detection of Matrix Metalloproteinase-8 (MMP-8)

by Jae Won Lee, Rowoon Park, Sangheon Jeon, Sung Hyun Kim, Young Woo Kwon, Dong-Wook Han and Suck Won Hong

Biosensors 2025, 15(10), 671; https://doi.org/10.3390/bios15100671 (registering DOI) - 4 Oct 2025

Abstract

Molecularly imprinted polymer (MIP) biosensors offer an attractive strategy for selective biomolecule detection, yet imprinting proteins with structural fidelity remains a major challenge. In this work, we present a rationally designed electrochemical biosensor for matrix metal-loproteinase-8 (MMP-8), a key salivary biomarker of periodontal [...] Read more.

Molecularly imprinted polymer (MIP) biosensors offer an attractive strategy for selective biomolecule detection, yet imprinting proteins with structural fidelity remains a major challenge. In this work, we present a rationally designed electrochemical biosensor for matrix metal-loproteinase-8 (MMP-8), a key salivary biomarker of periodontal disease. By integrating graphene oxide (GO) with electropolymerized poly(eriochrome black T, EBT) films on screen-printed carbon electrodes, the partially reduced GO interface enhanced electrical conductivity and facilitated the formation of well-defined poly(EBT) films with re-designed polymerization route, while template extraction generated artificial antibody-like sites capable of specific protein binding. The MIP-based electrodes were comprehensively validated through morphological, spectroscopic, and electrochemical analyses, demonstrating stable and selective recognition of MMP-8 against structurally similar interferents. Complementary density functional theory (DFT) modeling revealed energetically favorable interactions between the EBT monomer and catalytic residues of MMP-8, providing molecular-level insights into imprinting specificity. These experimental and computational findings highlight the importance of rational monomer selection and nanomaterial-assisted polymerization in achieving selective protein imprinting. This work presents a systematic approach that integrates electrochemical engineering, nanomaterial interfaces, and computational validation to address long-standing challenges in protein-based MIP biosensors. By bridging molecular design with practical sensing performance, this study advances the translational potential of MIP-based electrochemical biosensors for point-of-care applications. Full article

(This article belongs to the Special Issue Molecularly Imprinted Polymers-Based Biosensors)

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17 pages, 4089 KB

Open AccessArticle

Affinity-Based Copolymer Coating for Oriented Protein Immobilization in Biosensor Development

by Lorenzo Zarini, Thomas Carzaniga, Morena Pirotta, Francesco Damin, Dario Brambilla, Marcella Chiari, Ivan Bassanini, Paola Gagni, Alessandro Mussida, Luca Casiraghi, Marco Buscaglia and Laura Sola

Biosensors 2025, 15(10), 670; https://doi.org/10.3390/bios15100670 (registering DOI) - 4 Oct 2025

Abstract

Effective protein immobilization is a critical step in biosensor development, as it ensures the stability, functionality, and orientation of biomolecules on the sensor surface. Here, we present a novel affinity-based terpolymer coating designed to enhance protein immobilization for biosensor applications. The novelty lies [...] Read more.

Effective protein immobilization is a critical step in biosensor development, as it ensures the stability, functionality, and orientation of biomolecules on the sensor surface. Here, we present a novel affinity-based terpolymer coating designed to enhance protein immobilization for biosensor applications. The novelty lies in the incorporation of nitrilotriacetic acid (NTA) ligands directly into the polymeric chains, facilitating histidine-tagged protein oriented binding through a robust metal-chelating interaction. To validate the system, magnetic microbeads coated with the polymer were tested for their ability to bind native and His-tagged proteins. The results demonstrated the superior binding capacity, enhanced stability, and reversibility of the interactions compared to traditional coatings, which immobilize proteins through nucleophile reactions with amine residues. Moreover, enzyme immobilization tests confirmed that the polymer preserves enzymatic activity, highlighting its potential for biosensor applications requiring functional biomolecules. This innovative polymeric coating offers a fast, versatile, and scalable solution for next-generation biosensor platforms, paving the way for improved sensitivity, reliability, and accessibility in diagnostic and analytical technologies. Full article

(This article belongs to the Special Issue Bioassays and Biosensors for Rapid Detection and Analysis (2nd Edition))

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14 pages, 5634 KB

Open AccessArticle

Validation of Analytical Models for the Development of Non-Invasive Glucose Measurement Devices

by Bruna Gabriela Pedro, Fernanda Maltauro de Cordova, Yana Picinin Sandri Lissarassa, Fabricio Noveletto and Pedro Bertemes-Filho

Biosensors 2025, 15(10), 669; https://doi.org/10.3390/bios15100669 - 3 Oct 2025

Abstract

Non-invasive glucose monitoring remains a persistent challenge in the scientific literature due to the complexity of biological samples and the limitations of traditional optical methods. Although advances have been made in the use of near-infrared (NIR) spectrophotometry, the direct application of the Lambert–Beer [...] Read more.

Non-invasive glucose monitoring remains a persistent challenge in the scientific literature due to the complexity of biological samples and the limitations of traditional optical methods. Although advances have been made in the use of near-infrared (NIR) spectrophotometry, the direct application of the Lambert–Beer Law (LBL) to such systems has proven problematic, particularly due to the non-linear behavior observed in complex organic solutions. In this context, the objective of this work is to propose and validate a methodology for the determination of the extinction coefficient of glucose in blood, taking into account the limitations of the LBL and the specificities of molecular interactions. The method was optimized through an iterative process to provide consistent results over multiple replicates. Whole blood and plasma samples from two individuals were analyzed using spectrophotometry in the 700 nm to 1400 nm. The results showed that glucose has a high spectral sensitivity close to 975 nm.The extinction coefficients obtained for glucose (

α_{g}

) ranged from −0.0045 to −0.0053, and for insulin (

α_{i}

) from 0.000075 to 0.000078, with small inter-individual variations, indicating strong stability of these parameters. The non-linear behaviour observed in the relationship between absorbance, glucose and insulin concentrations might be explained by the changes imposed by both s and p orbitals of organic molecules. In order to make the LBL valid in this context, the extinction coefficients must be functions of the analyte concentrations, and the insulin concentration must also be a function of glucose. A regression model was found which allows to differentiate glucose from insulin concentration, by considering the cuvette thickness and sample absorbance at 965, 975, and 985 nm. It can also be concluded from experiments that wavelength of approximately 975 nm is more suitable for blood glucose calculation by using photometry. The final spectra are consistent with those reported in mid-infrared validation studies, suggesting that the proposed model encompasses the key aspects of glucose behavior in biological media. Full article

(This article belongs to the Special Issue Recent Advances in Glucose Biosensors)

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30 pages, 3358 KB

Open AccessReview

Exhaled Aldehydes and Ketones as Biomarkers of Lung Cancer and Diabetes: Review of Sensor Technologies for Early Disease Diagnosis

by Rafał Kiejzik, Tomasz Wasilewski and Wojciech Kamysz

Biosensors 2025, 15(10), 668; https://doi.org/10.3390/bios15100668 - 3 Oct 2025

Abstract

Exhaled breath (EB) contains numerous volatile organic compounds (VOCs) that can reflect pathological metabolic processes, making breath analysis a promising non-invasive diagnostic approach. In particular, volatile aldehydes and ketones have been identified as disease biomarkers in EB. Gas sensors are expected to play [...] Read more.

Exhaled breath (EB) contains numerous volatile organic compounds (VOCs) that can reflect pathological metabolic processes, making breath analysis a promising non-invasive diagnostic approach. In particular, volatile aldehydes and ketones have been identified as disease biomarkers in EB. Gas sensors are expected to play a crucial role in the diagnosis of numerous diseases at an early stage. Among the various available approaches, sensors stand out as especially attractive tools for diagnosing diseases such as lung cancer (LC) and diabetes, due to their affordability and operational simplicity. There is an urgent need in the field of disease detection for the development of affordable, non-invasive, and user-friendly sensors capable of detecting various biomarkers. Devices of the new generation should also demonstrate high repeatability of measurements and extended operational stability of the employed sensors. Due to these demands, the past few years have seen significant advancements in the development and implementation of electronic noses (ENs), which are composed of an array of sensors for the determination of VOCs present in EB. To meet these requirements, the development and integration of advanced receptor coatings on sensor transducers is essential. These coatings include nanostructured materials, molecularly imprinted polymers, and bioreceptors, which collectively enhance selectivity, sensitivity, and operational stability. However, reliable biomarker detection in point-of-care (PoC) mode remains a significant challenge, constrained by several factors. This review provides a comprehensive and critical evaluation of recent studies demonstrating that the detection of VOCs using gas sensor platforms enables disease detection and can be implemented in PoC mode. Full article

(This article belongs to the Special Issue Functional Materials for Biosensing Applications)

18 pages, 7440 KB

Open AccessArticle

The Impact of Dual-Wavefront Propagation of Electromagnetic Waves in Bio-Tissues on Imaging and In-Body Communications

by Lei Guo, Kamel Sultan, Fei Xue and Amin Abbosh

Biosensors 2025, 15(10), 667; https://doi.org/10.3390/bios15100667 - 3 Oct 2025

Abstract

Understanding how electromagnetic (EM) waves travel through different tissues is important for EM medical imaging, sensing, and in-body communication. It is known that EM waves in lossy bio-tissues are nonuniform and do not strictly follow the least time or least loss paths. Instead, [...] Read more.

Understanding how electromagnetic (EM) waves travel through different tissues is important for EM medical imaging, sensing, and in-body communication. It is known that EM waves in lossy bio-tissues are nonuniform and do not strictly follow the least time or least loss paths. Instead, they exhibit two distinct wavefronts: the phase wavefront and the amplitude wavefront, which are generally oriented at different angles. The impact of that on imaging and in-body communications is investigated and validated through comprehensive analysis and full-wave EM simulations. Additionally, the impact of a matching medium, commonly used to reduce antenna–skin interface reflections in medical EM applications, on the direction of EM wavefronts, travel time, phase changes, and attenuation is analyzed and quantified. The results show that the Fermat principle of least travel time, often used to estimate EM wave travel time for localization in medical imaging and wireless endoscopy, is only accurate when the loss tangent or dissipation factor of both the matching medium and tissues is very low. Otherwise, the results will be inaccurate, and the dual wavefronts should be considered. The presented analysis and results provide guidance on EM wave travel time and the direction of phase and amplitude wavefronts. This information is valuable for developing reliable processing algorithms for sensing, imaging, and in-body communication. Full article

(This article belongs to the Special Issue Biosensing and Diagnosis—2nd Edition)

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11 pages, 1143 KB

Open AccessCommunication

Development of Nanobody-Based Sandwich ELISA Resistant to SpA Interference for Sensitive Detection of Staphylococcal Enterotoxin A

by Chenghao Hu, Di Wang, Yangwei Ou, Ruoyu Li, Qi Chen and Peng Liu

Biosensors 2025, 15(10), 666; https://doi.org/10.3390/bios15100666 - 3 Oct 2025

Abstract

Staphylococcus aureus is a major pathogen responsible for staphylococcal food poisoning (SFP), with its pathogenicity primarily dependent on staphylococcal enterotoxins (SEs). Among these, staphylococcal enterotoxin A (SEA) is a critical risk factor due to its high toxicity, high detection rate (accounting for 80% [...] Read more.

Staphylococcus aureus is a major pathogen responsible for staphylococcal food poisoning (SFP), with its pathogenicity primarily dependent on staphylococcal enterotoxins (SEs). Among these, staphylococcal enterotoxin A (SEA) is a critical risk factor due to its high toxicity, high detection rate (accounting for 80% of SFP cases), strong thermal stability, and resistance to hydrolysis. Traditional SEA immunoassays, such as enzyme-linked immunosorbent assay (ELISA), are prone to false-positive results caused by nonspecific binding interference from S. aureus surface protein A (SpA). In recent years, nanobodies (single-domain heavy-chain antibodies) have emerged as an ideal alternative to address SpA interference owing to their small molecular weight (15 kDa), high affinity, robust stability, and lack of Fc regions. In this study, based on a previously developed highly specific monoclonal antibody against SEA (mAb-4C6), four anti-SEA nanobodies paired with mAb-4C6 were obtained through two-part (four-round) of biopanning from a naive nanobody phage display library. Among these, SEA-4-20 and SEA-4-31 were selected as optimal candidates and paired with mAb-4C6 to construct double-antibody sandwich ELISAs. The detection limits for SEA were 0.135 ng/mL and 0.137 ng/mL, respectively, with effective elimination of SpA interference. This approach provides a reliable tool for rapid and accurate detection of SEA in food, clinical, and environmental samples. Full article

(This article belongs to the Special Issue Immunoassays and Biosensing (2nd Edition))

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20 pages, 4532 KB

Open AccessArticle

Harnessing in Silico Design for Electrochemical Aptasensor Optimization: Detection of Okadaic Acid (OA)

by Margherita Vit, Sondes Ben-Aissa, Alfredo Rondinella, Lorenzo Fedrizzi and Sabina Susmel

Biosensors 2025, 15(10), 665; https://doi.org/10.3390/bios15100665 - 3 Oct 2025

Abstract

The urgent need for advanced analytical tools for environmental monitoring and food safety drives the development of novel biosensing approaches and solutions. A computationally driven workflow for the development of a rapid electrochemical aptasensor for okadaic acid (OA), a critical marine biotoxin, is [...] Read more.

The urgent need for advanced analytical tools for environmental monitoring and food safety drives the development of novel biosensing approaches and solutions. A computationally driven workflow for the development of a rapid electrochemical aptasensor for okadaic acid (OA), a critical marine biotoxin, is reported. The core of this strategy is a rational design process, where in silico modeling was employed to optimize the biological recognition element. A 63-nucleotide aptamer was successfully truncated to a highly efficient 31-nucleotide variant. Molecular docking simulations confirmed the high binding affinity of the minimized aptamer and guided the design of the surface immobilization chemistry to ensure robust performance. The fabricated sensor, which utilizes a ferrocene-labeled aptamer, delivered a sensitive response with a detection limit of 2.5 nM (n = 5) over a linear range of 5–200 nM. A significant advantage for practical applications is the remarkably short assay time of 5 min. The sensor’s applicability was successfully validated in complex food matrices, achieving excellent recovery rates of 82–103% in spiked mussel samples. This study establishes an integrated computational–experimental methodology that streamlines the development of high-performance biosensors for critical food safety and environmental monitoring challenges. Full article

(This article belongs to the Special Issue Sensors for Environmental Monitoring and Food Safety—2nd Edition)

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15 pages, 1974 KB

Open AccessArticle

A Flexible Electrochemical Sensor Based on Porous Ceria Hollow Microspheres Nanozyme for Sensitive Detection of H₂O₂

by Jie Huang, Xuanda He, Shuang Zou, Keying Ling, Hongying Zhu, Qijia Jiang, Yuxuan Zhang, Zijian Feng, Penghui Wang, Xiaofei Duan, Haiyang Liao, Zheng Yuan, Yiwu Liu and Jinghua Tan

Biosensors 2025, 15(10), 664; https://doi.org/10.3390/bios15100664 - 2 Oct 2025

Abstract

The development of cost-effective and highly sensitive hydrogen peroxide (H₂O₂) biosensors with robust stability is critical due to the pivotal role of H₂O₂ in biological processes and its broad utility across various applications. In this work, [...] Read more.

The development of cost-effective and highly sensitive hydrogen peroxide (H₂O₂) biosensors with robust stability is critical due to the pivotal role of H₂O₂ in biological processes and its broad utility across various applications. In this work, porous ceria hollow microspheres (CeO₂-phm) were synthesized using a solvothermal synthesis method and employed in the construction of an electrochemical biosensor for H₂O₂ detection. The resulting CeO₂-phm featured a uniform pore size centered at 3.4 nm and a high specific surface area of 168.6 m²/g. These structural attributes contribute to an increased number of active catalytic sites and promote efficient electrolyte penetration and charge transport, thereby enhancing its electrochemical sensing performance. When integrated into screen-printed carbon electrodes (CeO₂-phm/cMWCNTs/SPCE), the CeO₂-phm/cMWCNTs/SPCE-based biosensor exhibited a wide linear detection range from 0.5 to 450 μM, a low detection limit of 0.017 μM, and a high sensitivity of 2070.9 and 2161.6 μA·mM⁻¹·cm⁻²—surpassing the performance of many previously reported H₂O₂ sensors. In addition, the CeO₂-phm/cMWCNTs/SPCE-based biosensor possesses excellent anti-interference performance, repeatability, reproducibility, and stability. Its effectiveness was further validated through successful application in real sample analysis. Hence, CeO₂-phm with solvothermal synthesis has great potential applications as a sensing material for the quantitative determination of H₂O₂. Full article

(This article belongs to the Special Issue Advances in Nanozyme-Based Biosensors)

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16 pages, 1003 KB

Open AccessArticle

Double-Layered Microphysiological System Made of Polyethylene Terephthalate with Trans-Epithelial Electrical Resistance Measurement Function for Uniform Detection Sensitivity

by Naokata Kutsuzawa, Hiroko Nakamura, Laner Chen, Ryota Fujioka, Shuntaro Mori, Noriyuki Nakatani, Takahiro Yoshioka and Hiroshi Kimura

Biosensors 2025, 15(10), 663; https://doi.org/10.3390/bios15100663 - 2 Oct 2025

Abstract

Microphysiological systems (MPSs) have emerged as alternatives to animal testing in drug development, following the FDA Modernization Act 2.0. Double-layer channel-type MPS chips with porous membranes are widely used for modeling various organs, including the intestines, blood–brain barrier, renal tubules, and lungs. However, [...] Read more.

Microphysiological systems (MPSs) have emerged as alternatives to animal testing in drug development, following the FDA Modernization Act 2.0. Double-layer channel-type MPS chips with porous membranes are widely used for modeling various organs, including the intestines, blood–brain barrier, renal tubules, and lungs. However, these chips faced challenges owing to optical interference caused by light scattering from the porous membrane, which hinders cell observation. Trans-epithelial electrical resistance (TEER) measurement offers a non-invasive method for assessing barrier integrity in these chips. However, existing electrode-integrated MPS chips for TEER measurement have non-uniform current densities, leading to compromised measurement accuracy. Additionally, chips made from polydimethylsiloxane have been associated with drug absorption issues. This study developed an electrode-integrated MPS chip for TEER measurement with a uniform current distribution and minimal drug absorption. Through a finite element method simulation, electrode patterns were optimized and incorporated into a polyethylene terephthalate (PET)-based chip. The device was fabricated by laminating PET films, porous membranes, and patterned gold electrodes. The chip’s performance was evaluated using a perfused Caco-2 intestinal model. TEER levels increased and peaked on day 5 when cells formed a monolayer, and then they decreased with the development of villi-like structures. Concurrently, capacitance increased, indicating microvilli formation. Exposure to staurosporine resulted in a dose-dependent reduction in TEER, which was validated by immunostaining, indicating a disruption of the tight junction. This study presents a TEER measurement MPS platform with a uniform current density and reduced drug absorption, thereby enhancing TEER measurement reliability. This system effectively monitors barrier integrity and drug responses, demonstrating its potential for non-animal drug-testing applications. Full article

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

22 pages, 26488 KB

Open AccessArticle

Lightweight Deep Learning Approaches on Edge Devices for Fetal Movement Monitoring

by Atcharawan Rattanasak, Talit Jumphoo, Kasidit Kokkhunthod, Wongsathon Pathonsuwan, Rattikan Nualsri, Sittinon Thanonklang, Pattama Tongdee, Porntip Nimkuntod, Monthippa Uthansakul and Peerapong Uthansakul

Biosensors 2025, 15(10), 662; https://doi.org/10.3390/bios15100662 - 2 Oct 2025

Abstract

Fetal movement monitoring (FMM) is crucial for assessing fetal well-being, traditionally relying on clinical assessments or maternal perception, each with inherent limitations. This study presents a novel lightweight deep learning framework for real-time FMM on edge devices. Data were collected from 120 participants [...] Read more.

Fetal movement monitoring (FMM) is crucial for assessing fetal well-being, traditionally relying on clinical assessments or maternal perception, each with inherent limitations. This study presents a novel lightweight deep learning framework for real-time FMM on edge devices. Data were collected from 120 participants using a wearable device equipped with an inertial measurement unit, which captured both accelerometer and gyroscope data, coupled with a rigorous two-stage labeling protocol integrating maternal perception and ultrasound validation. We addressed class imbalance using virtual-rotation-based augmentation and adaptive clustering-based undersampling. The data were transformed into spectrograms using the Short-Time Fourier Transform, serving as input for deep learning models. To ensure model efficiency suitable for resource-constrained microcontrollers, we employed knowledge distillation, transferring knowledge from larger, high-performing teacher models to compact student architectures. Post-training integer quantization further optimized the models, reducing the memory footprint by 74.8%. The final optimized model achieved a sensitivity (SEN) of 90.05%, a precision (PRE) of 87.29%, and an F1-score (F1) of 88.64%. Practical energy assessments showed continuous operation capability for approximately 25 h on a single battery charge. Our approach offers a practical framework adaptable to other medical monitoring tasks on edge devices, paving the way for improved prenatal care, especially in resource-limited settings. Full article

(This article belongs to the Section Wearable Biosensors)

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14 pages, 3412 KB

Open AccessArticle

MoS₂ Nanoflower-Based Colorimetric and Photothermal Dual-Mode Lateral Flow Immunoassay for Highly Sensitive Detection of Pathogens

by Meimei Xu, Shuai Zhao, Yusi Peng and Yong Yang

Biosensors 2025, 15(10), 661; https://doi.org/10.3390/bios15100661 - 2 Oct 2025

Abstract

The single colorimetric signal readout mode of traditional lateral flow immunoassay (LFIA), which relies on gold nanoparticles (Au NPs), is inadequate to meet the growing demand for detection in terms of sensitivity, accuracy, and flexibility. Herein, we reported a novel colorimetric and photothermal [...] Read more.

The single colorimetric signal readout mode of traditional lateral flow immunoassay (LFIA), which relies on gold nanoparticles (Au NPs), is inadequate to meet the growing demand for detection in terms of sensitivity, accuracy, and flexibility. Herein, we reported a novel colorimetric and photothermal dual-mode LFIA (dLFIA) based on MoS₂ nanoflowers for rapid detection of severe acute respiratory syndrome coronavirus 2 nucleocapsid protein (SARS-CoV-2 NP). Benefiting from the strong color-producing ability and near-infrared absorption of MoS₂ nanoflowers, the visual limits of detection in colorimetric and photothermal modes were 1 and 0.1 ng/mL, respectively. The limit of detection for quantitative analysis in photothermal mode was 48 pg/mL, with a sensitivity about 10~208 times higher than that of Au NPs-LFIA. Additionally, the dLFIA strips exhibited excellent specificity, good reproducibility, and satisfactory recovery when detected the simulated nasal swab samples, possessing good application prospect. Full article

(This article belongs to the Special Issue Nanomaterial-Based Biosensors for Point-of-Care Testing)

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38 pages, 2377 KB

Open AccessReview

CRISPR-Cas-Based Diagnostics in Biomedicine: Principles, Applications, and Future Trajectories

by Zhongwu Zhou, Il-Hoon Cho and Ulhas S. Kadam

Biosensors 2025, 15(10), 660; https://doi.org/10.3390/bios15100660 - 2 Oct 2025

Abstract

CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats)-Cas (CRISPR-associated) systems, originally identified as prokaryotic adaptive immune mechanisms, have rapidly evolved into powerful tools for molecular diagnostics. Leveraging their precise nucleic acid targeting capabilities, CRISPR diagnostics offer rapid, sensitive, and specific detection solutions for a [...] Read more.

CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats)-Cas (CRISPR-associated) systems, originally identified as prokaryotic adaptive immune mechanisms, have rapidly evolved into powerful tools for molecular diagnostics. Leveraging their precise nucleic acid targeting capabilities, CRISPR diagnostics offer rapid, sensitive, and specific detection solutions for a wide array of targets. This review delves into the fundamental principles of various Cas proteins (e.g., Cas9, Cas12a, Cas13a) and their distinct mechanisms of action (cis- and trans-cleavage). It highlights the diverse applications spanning infectious disease surveillance, cancer biomarker detection, and genetic disorder screening, emphasizing key advantages such as speed, high sensitivity, specificity, portability, and cost-effectiveness, particularly for point-of-care (POC) testing in resource-limited settings. The report also addresses current challenges, including sensitivity limitations without pre-amplification, specificity issues, and complex sample preparation, while exploring promising future trajectories like the integration of artificial intelligence (AI) and the development of universal diagnostic platforms to enhance clinical translation. Full article

(This article belongs to the Special Issue Aptamer-Based Biosensors for Point-of-Care Diagnostics)

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13 pages, 1866 KB

Open AccessArticle

Development of Freshness Indicator (FI) for Skate Sashimi (Zearaja chilensis) to Detect Trimethylamine Content During Storage

by Kyung-Jik Lim, Yoon-Gil Kim, Yu-Jin Heo and Han-Seung Shin

Biosensors 2025, 15(10), 659; https://doi.org/10.3390/bios15100659 - 2 Oct 2025

Abstract

The seafood industry is increasingly adopting intelligent packaging to preserve product quality and improve freshness transparency. This study developed and evaluated a pH-sensitive freshness indicator (FI) for skate sashimi (Zearaja chilensis). This product is consumed at varying stages of fermentation. The [...] Read more.

The seafood industry is increasingly adopting intelligent packaging to preserve product quality and improve freshness transparency. This study developed and evaluated a pH-sensitive freshness indicator (FI) for skate sashimi (Zearaja chilensis). This product is consumed at varying stages of fermentation. The FI incorporated bromothymol blue (BTB) and bromocresol purple (BCP) in a polymer matrix. It targeted volatile basic nitrogen (VBN) compounds, with trimethylamine (TMA) as the primary marker. As freshness declined, VBN compounds accumulated in the package headspace and caused a gradual FI color change from yellow to blue through pH variation. ΔE increased from 7.72 on day 2 to 23.52 on day 3. This marked the onset of visible color change and the FI reached full blue by day 7. Headspace solid-phase microextraction (HS-SPME) and gas chromatography–flame ionization detection (GC-FID) quantified monomethylamine (MMA), dimethylamine (DMA) and TMA throughout storage. ΔE correlated strongly with total bacterial count (TBC, r = 0.978), pH (r = 0.901) and TMA (r = 0.888). These results indicate that microbial growth, alkalinity increase and amine production were closely associated with color transitions. The FI reliably tracked freshness loss in skate sashimi. It has potential to enhance consumer transparency and strengthen quality control in the seafood supply chain. Full article

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

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38 pages, 2063 KB

Open AccessReview

Nanostructured Materials in Glucose Biosensing: From Fundamentals to Smart Healthcare Applications

by Rajaram Rajamohan and Seho Sun

Biosensors 2025, 15(10), 658; https://doi.org/10.3390/bios15100658 - 2 Oct 2025

Abstract

The rapid development of nanotechnology has significantly transformed the design and performance of glucose biosensors, leading to enhanced sensitivity, selectivity, and real-time monitoring capabilities. This review highlights recent advances in glucose-sensing platforms facilitated by nanomaterials, including metal and metal oxide nanoparticles, carbon-based nanostructures, [...] Read more.

The rapid development of nanotechnology has significantly transformed the design and performance of glucose biosensors, leading to enhanced sensitivity, selectivity, and real-time monitoring capabilities. This review highlights recent advances in glucose-sensing platforms facilitated by nanomaterials, including metal and metal oxide nanoparticles, carbon-based nanostructures, two-dimensional materials, and metal–organic frameworks (MOFs). The integration of these nanoscale materials into electrochemical, optical, and wearable biosensors has addressed longstanding challenges associated with enzyme stability, detection limits, and invasiveness. Special emphasis is placed on non-enzymatic glucose sensors, flexible and wearable devices, and hybrid nanocomposite systems. The multifunctional properties of nanomaterials, such as large surface area, excellent conductivity, and biocompatibility, have enabled the development of next-generation sensors for clinical, point-of-care, and personal healthcare applications. The review also discusses emerging trends such as biodegradable nanosensors, AI-integrated platforms, and smart textiles, which are poised to drive the future of glucose monitoring toward more sustainable and personalized healthcare solutions. Full article

(This article belongs to the Special Issue Recent Advances in Glucose Biosensors)

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27 pages, 4737 KB

Open AccessReview

Recent Progress in Polyphenol-Based Hydrogels for Wound Treatment and Monitoring

by Lulu Liu, Wenrui Ma, Junju Wang, Xiang Wang and Shunbo Li

Biosensors 2025, 15(10), 657; https://doi.org/10.3390/bios15100657 - 1 Oct 2025

Abstract

Hydrogels have received increasing attention in biomedical applications owing to their controllable physical and chemical properties, high biocompatibility, and structural similarity to natural biological tissues. Among them, polyphenol-based hydrogels stand out due to the inherent antibacterial, antioxidant, and anti-inflammatory properties, along with their [...] Read more.

Hydrogels have received increasing attention in biomedical applications owing to their controllable physical and chemical properties, high biocompatibility, and structural similarity to natural biological tissues. Among them, polyphenol-based hydrogels stand out due to the inherent antibacterial, antioxidant, and anti-inflammatory properties, along with their excellent biocompatibility and functional versatility. These features make them highly promising for advanced wound treatment and monitoring applications. This review highlights recent advances in polyphenol-based hydrogels for wound management and monitoring, with an emphasis on their innovative design and integrated functionality. Firstly, an overview of structure, classification, and biological function of polyphenols is introduced. On this basis, the construction methods, functions, and applications of several representative polyphenol-based hydrogels are discussed. Then, the application of polyphenol-based hydrogels on wound treatment and monitoring is comprehensively summarized. In the end, the recently developed microneedles based on polyphenol hydrogels in combination with artificial intelligence in wound management are also discussed. This review aims to provide valuable insights for advancing polyphenol-based hydrogels, not only in their design, preparation, and application for wound healing and intelligent management but also in their future development potential. Full article

(This article belongs to the Special Issue Feature Paper in Biosensor and Bioelectronic Devices 2025)

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25 pages, 6394 KB

Open AccessReview

Artificial Intelligence-Assisted Nanosensors for Clinical Diagnostics: Current Advances and Future Prospects

by Shuo Yin

Biosensors 2025, 15(10), 656; https://doi.org/10.3390/bios15100656 - 1 Oct 2025

Abstract

The integration of artificial intelligence (AI) with various diagnostic nanosensors has opened up new horizons in clinics recently. AI technology offers enhanced sensitivity, accuracy, specificity, and real-time analysis for disease diagnostics. This review focuses on the recent advances in AI-assisted nanosensors for the [...] Read more.

The integration of artificial intelligence (AI) with various diagnostic nanosensors has opened up new horizons in clinics recently. AI technology offers enhanced sensitivity, accuracy, specificity, and real-time analysis for disease diagnostics. This review focuses on the recent advances in AI-assisted nanosensors for the diagnosis of different diseases in clinical applications. Critical roles of AI in sensor design, optimization, signal processing, and clinical decision support are highlighted. Furthermore, challenges such as limited datasets, regulatory hurdles, and data privacy are discussed, along with future opportunities. This review aims to provide a comprehensive introduction and perspectives on how AI-driven nanosensors are transforming clinical diagnostics and shaping the future of precise medicine. Full article

(This article belongs to the Special Issue Nanosensors for Bioanalysis)

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21 pages, 7155 KB

Open AccessArticle

SERS Detection of Environmental Variability in Balneary Salt Lakes During Tourist Season: A Pilot Study

by Csilla Molnár, Karlo Maškarić, Lucian Barbu-Tudoran, Tudor Tămaș, Ilirjana Bajama and Simona Cîntă Pînzaru

Biosensors 2025, 15(10), 655; https://doi.org/10.3390/bios15100655 - 1 Oct 2025

Abstract

This pilot study uses Raman spectroscopy and SERS to monitor monthly water composition changes in two adjacent hypersaline lakes (L1 and L2) at a balneary resort, during the peak tourist season (May–October 2023). In situ pH and electrical conductivity (EC) measurements, along with [...] Read more.

This pilot study uses Raman spectroscopy and SERS to monitor monthly water composition changes in two adjacent hypersaline lakes (L1 and L2) at a balneary resort, during the peak tourist season (May–October 2023). In situ pH and electrical conductivity (EC) measurements, along with evaporite analyses, complemented the spectroscopic data. Although traditionally considered similar, the lakes frequently raise public questions about their relative bathing benefits. While not directly addressing the therapeutic effects, the study reveals distinct physicochemical profiles between the lakes. Raman data showed consistently higher sulfate levels in L2, a trend also observed in winter monitoring. pH levels were higher in L1 (8–9.8) than in L2 (7.2–8), except for one October depth reading. This trend held during winter, except in April. Surface waters showed more variability and slightly higher values than those at 1 m depth. SERS spectra featured β-carotene peaks, linked to cyanobacteria, and Ag–Cl bands, indicating nanoparticle aggregation from inorganic ions. SERS intensity strongly correlated with pH and EC, especially in L2 (r = 0.96), suggesting stable surface–depth chemistry. L1 exhibited more monthly variability, likely due to differing biological activity. Although salinity and EC were not linearly correlated at high salt levels, both reflected seasonal trends. The integration of Raman, SERS, and physicochemical data proves effective for monitoring hypersaline lake dynamics, offering a valuable tool for environmental surveillance and therapeutic water quality assessment, in support of evidence-based water management and therapeutic use of salt lakes, aligning with goals for sustainable medical tourism and environmental stewardship. Full article

(This article belongs to the Special Issue Advanced SERS Biosensors for Detection and Analysis)

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14 pages, 1538 KB

Open AccessArticle

Duplex EIS Sensor for Salmonella Typhi and Aflatoxin B1 Detection in Soil Runoff

by Kundan Kumar Mishra, Krupa M Thakkar, Sumana Karmakar, Vikram Narayanan Dhamu, Sriram Muthukumar and Shalini Prasad

Biosensors 2025, 15(10), 654; https://doi.org/10.3390/bios15100654 - 1 Oct 2025

Abstract

Monitoring contamination in soil and food systems remains vital for ensuring environmental and public health, particularly in agriculture-intensive regions. Existing laboratory-based techniques are often time-consuming, equipment-dependent, and impractical for rapid on-site screening. In this study, we present a portable, non-faradaic electrochemical impedance-based sensing [...] Read more.

Monitoring contamination in soil and food systems remains vital for ensuring environmental and public health, particularly in agriculture-intensive regions. Existing laboratory-based techniques are often time-consuming, equipment-dependent, and impractical for rapid on-site screening. In this study, we present a portable, non-faradaic electrochemical impedance-based sensing platform capable of simultaneously detecting Salmonella Typhimurium (S. Typhi) and Aflatoxin B1 in spiked soil run-off samples. The system employs ZnO-coated electrodes functionalized with crosslinker for covalent antibody immobilization, facilitating selective, label-free detection using just 5 µL of sample. The platform achieves a detection limit of 1 CFU/mL for S. Typhi over a linear range of 10–10⁵ CFU/mL and 0.001 ng/mL for Aflatoxin B1 across a dynamic range of 0.01–40.96 ng/mL. Impedance measurements captured with a handheld potentiostat were strongly correlated with benchtop results (R² > 0.95), validating its reliability in field settings. The duplex sensor demonstrates high precision with recovery rates above 80% and coefficient of variation below 15% in spiked samples. Furthermore, machine learning classification of safe versus contaminated samples yielded an ROC-AUC > 0.8, enhancing its decision-making capability. This duplex sensing platform offers a robust, user-friendly solution for real-time environmental and food safety surveillance. Full article

(This article belongs to the Special Issue Bioassays and Biosensors for Rapid Detection and Analysis (2nd Edition))

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18 pages, 4824 KB

Open AccessReview

Review of Microchip Analytical Methods Coupled with Aptamer-Based Signal Amplification Strategies for High-Sensitivity Bioanalytical Applications

by Xudong Xue, Yanli Hou, Caihua Hu and Yan Zhang

Biosensors 2025, 15(10), 653; https://doi.org/10.3390/bios15100653 - 1 Oct 2025

Abstract

Aptamers have many advantages, including facile synthesis and a high affinity and good selectivity toward their targets. Therefore, aptamer-based biosensors have become increasingly popular for the detection of different bioanalytical substances. Microchip-based analytical detection platforms offer significant advantages for the detection of different [...] Read more.

Aptamers have many advantages, including facile synthesis and a high affinity and good selectivity toward their targets. Therefore, aptamer-based biosensors have become increasingly popular for the detection of different bioanalytical substances. Microchip-based analytical detection platforms offer significant advantages for the detection of different analytes, including their ease of operation, high throughput, cost-effectiveness, and high sensitivity. Aptamer-based signal amplification techniques have been combined with microchips to sensitively detect bioanalytical substances due to their stable reactions, easy operation, and specificity in biomedical science and environmental fields. This review summarizes representative articles about aptamer signal amplification strategies on microchips for the detection of bioanalytical substances, as well as their advantages and challenges for specific applications. We highlight the accomplishments and shortcomings of aptamer signal amplification strategies on microchips and discuss the direction of development and prospects of aptamer signal amplification strategies on microchips. Full article

(This article belongs to the Special Issue Advanced Lab-on-Chip and Micro-Systems for Manipulation and Bio-Detection)

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