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Biosensors, Volume 15, Issue 9 (September 2025) – 46 articles

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26 pages, 5753 KB  
Review
Metal–Phenolic Networks for Sensing Applications
by Ning Xia, Sirui Liang, Dehua Deng, Yong Chang and Xinyao Yi
Biosensors 2025, 15(9), 600; https://doi.org/10.3390/bios15090600 - 11 Sep 2025
Abstract
The preparation of new inorganic–organic hybrid materials is beneficial for the development of powerful sensing methods and technologies. Polyphenols, a type of organic molecule containing phenolic hydroxyl groups, are widely present in natural plants and have beneficial effects on human health. Metal ions [...] Read more.
The preparation of new inorganic–organic hybrid materials is beneficial for the development of powerful sensing methods and technologies. Polyphenols, a type of organic molecule containing phenolic hydroxyl groups, are widely present in natural plants and have beneficial effects on human health. Metal ions are ubiquitous in nature and play an important role in the development of inorganic–organic hybrid materials. Metal–phenolic networks (MPNs) are formed by the self-assembly of metal ions and polyphenols through dynamic coordination bonds. Due to their mild synthesis conditions, facilely engineered functionalities, and multiple modification strategies, MPNs have become potential platforms for sensing applications. Timely understanding of the function and application of MPNs in sensing fields will facilitate the development of novel chemical and biological sensors and devices. This article summarizes the typical preparation methods and excellent advantages of MPNs and focuses on their latest achievements in sensing applications. We highlight representative MPN-based sensing examples, including the direct detection of small molecules and biological species, immunoassays, bioimaging, and wearable devices. Finally, the prospects and future directions of MPNs in sensing fields are addressed. Full article
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20 pages, 6524 KB  
Article
Foreign Body Reaction to Neural Implants: A Comparative Study of Polymer Toxicity and Tissue Response
by Ciara Makievskaya, Anna Brezgunova, Nadezda Andrianova, Evgeny Kelm, Maria Solovyova, Gelena Naumova, Alina Zeinalova, Olga Gancharova, Tatiana Bushkova, Daniil Kozlov, Valery Putlayev, Pavel Evdokimov, Alexander Petrov, Mikhail Lebedev, Egor Plotnikov and Vasily Popkov
Biosensors 2025, 15(9), 599; https://doi.org/10.3390/bios15090599 - 11 Sep 2025
Abstract
This study investigated the toxicity of ten polymer materials intended for the development of invasive neural interfaces improving the treatment of neurological diseases. Most of the materials for neural implants can cause traumatization of the surrounding tissue, inflammation, and foreign body reaction. In [...] Read more.
This study investigated the toxicity of ten polymer materials intended for the development of invasive neural interfaces improving the treatment of neurological diseases. Most of the materials for neural implants can cause traumatization of the surrounding tissue, inflammation, and foreign body reaction. In this study, in vitro and in vivo toxicity assessment was performed for nylon 618 (NY), polycaprolactone (PCL), polyethylene glycol diacrylate (PEGDA), polydimethylsiloxane (PDMS), polyethylene terephthalate (PET), polylactide (PLA), thermoplastic polyurethane (TPU), polypropylene (PP), polyethylene terephthalate glycol (PET-G), and polyimide (PI). The biocompatibility of these ten materials was assessed based on cell adhesion, growth and cytotoxicity on neural (PC-12) and fibroblast (NRK-49F) cultures. Furthermore, brain tissue responses to the implanted phantom scaffolds were analyzed in rats. According to these measurements, PI showed the highest compatibility for both cell types. PEGDA exhibited cytotoxic effects, low cell adhesion and the strongest foreign body reaction, including fibrosis and multinucleated cell formation. The other polymers showed lower pathological responses which makes them potentially usable for neural interfacing. We conclude that PEGDA appears to be unsuitable for long-term use due to adverse tissue and cellular reactions, whereas PI, PLA, PDMS and TPU hold promise as materials for safe and effective neural interface applications. Full article
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19 pages, 7792 KB  
Article
Evaluation of Fluorescence Detection Algorithms for Efficient ROI Setting in Low-Cost Real-Time PCR Systems
by Seul-Bit-Na Koo, Ji-Soo Hwang, Chan-Young Park and Deuk-Ju Lee
Biosensors 2025, 15(9), 598; https://doi.org/10.3390/bios15090598 - 10 Sep 2025
Abstract
This study proposes a region of interest (ROI) setting method to improve the accuracy and efficiency of fluorescence detection in a compact real-time multiplex fluorescence PCR system. Conventional commercial real-time PCR systems are limited in point-of-care (POC) environments due to their high cost [...] Read more.
This study proposes a region of interest (ROI) setting method to improve the accuracy and efficiency of fluorescence detection in a compact real-time multiplex fluorescence PCR system. Conventional commercial real-time PCR systems are limited in point-of-care (POC) environments due to their high cost and complex optical structures. To address this issue, we developed a low-cost, compact system using an open-platform camera and a Fresnel lens. However, in such a simply structured system, variations between the wells of the polymerase chain reaction (PCR) plate may affect the accuracy of fluorescence detection. In this study, after capturing images with a CMOS camera, we propose two ROI image processing algorithms. The proposed algorithms reliably extract fluorescence signals and compare ROI deviations caused by variations between wells to determine whether physical correction is necessary. To validate the system, we performed comparative analysis of real-time DNA amplification images and fluorescence dye images collected over multiple periods. Based on evaluations using manual detection as a reference, it was confirmed that even a simple algorithm can achieve stable fluorescence detection while minimizing ROI distortion. This study presents an efficient method for enhancing the accuracy of quantitative fluorescence analysis in small PCR systems and is expected to contribute to improving the performance of point-of-care diagnostics, thereby increasing accessibility to on-site diagnostics in the future. Full article
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11 pages, 2701 KB  
Article
Simulation-Based Performance Assessment of Bulk Junctionless FET with Asymmetric Source/Drain for Ultrasensitive Detection of Biomolecules
by Jeongmin Son, M. Meyyappan and Kihyun Kim
Biosensors 2025, 15(9), 597; https://doi.org/10.3390/bios15090597 - 10 Sep 2025
Abstract
Bio field-effect transistors (BioFETs) have attracted attention for their ability to rapidly detect physiological data with a simple structure. While conventional BioFETs offer high sensitivity, they often require reference electrodes or involve complex fabrication processes. A recently proposed bulk junctionless BioFET (Bulk JL-BioFET) [...] Read more.
Bio field-effect transistors (BioFETs) have attracted attention for their ability to rapidly detect physiological data with a simple structure. While conventional BioFETs offer high sensitivity, they often require reference electrodes or involve complex fabrication processes. A recently proposed bulk junctionless BioFET (Bulk JL-BioFET) features a simple fabrication process to address these issues. This structure utilizes a depletion region formed by a p-n junction, as the active layer is directly in contact with a substrate of the opposite type. As a result, the device can operate effectively with only two terminals—drain and source—without the need for a reference electrode. In this study, we propose a novel Bulk JL-BioFET, incorporating a doped field stop layer and an asymmetric source/drain structure, and verify its performance through simulations. The doped field stop layer blocks the electric field expansion, enhancing channel modulation, while the asymmetric source/drain structure promotes electron injection, reducing the on-off swing voltage and turn-on voltage. This improves the electrical performance, enabling lower power consumption and higher sensitivity. Simulation results show that the combination of these two novel features results in a sensitivity increase of approximately 30-fold. Moreover, high sensitivity was observed below the turn-on voltage region for all the structures when analyzing the sensitivity with overdrive voltage, identifying the optimal operating conditions. This study suggests that the combination of the doped field stop layer and asymmetric source/drain structure is an effective design strategy to maximize the sensing performance of BioFETs while minimizing power consumption. Full article
(This article belongs to the Special Issue Transistor-Based Biosensors and Their Applications)
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14 pages, 4226 KB  
Article
Pathogen-on-a-Chip: Impedance-Based Detection of Biofilm Formation of Staphylococcus aureus and Staphylococcus epidermidis
by Bengisu Yöney, Radka Obořilová, Karel Lacina, Zdeněk Farka and Petr Skládal
Biosensors 2025, 15(9), 596; https://doi.org/10.3390/bios15090596 - 10 Sep 2025
Abstract
Bacterial biofilms are complex microbial communities that contribute to the pathogenesis of chronic infections. Therefore, it is crucial to detect biofilm-associated infections in early stages as their delayed treatment becomes more complicated. Herein, we describe a label-free electrochemical impedance spectroscopy (EIS) method for [...] Read more.
Bacterial biofilms are complex microbial communities that contribute to the pathogenesis of chronic infections. Therefore, it is crucial to detect biofilm-associated infections in early stages as their delayed treatment becomes more complicated. Herein, we describe a label-free electrochemical impedance spectroscopy (EIS) method for detecting biofilm formation by Staphylococcus aureus and Staphylococcus epidermidis. Printed circuit board-based biamperometric gold electrodes were modified with poly-L-lysine to enhance bacterial attachment to the sensor surface. Formation and inhibition of biofilms were evaluated based on changes in charge transfer resistance (Rct). The control Rct value increased by ~90 kΩ for S. epidermidis biofilm and by ~60 kΩ for S. aureus biofilms. Antibiotic-treated samples exhibited similar values to those using the control. In addition, biofilm formation was evaluated through optical microscopy using safranin staining, and the micrographs suggest significant biomass on the electrodes, whereas the control appeared clear. Atomic force microscopy was used to visualize the biofilm on the electrode surface, obtain cross-sectional profiles, and evaluate its roughness. The roughness parameters indicate that S. aureus forms a rougher biofilm than S. epidermidis, while S. epidermidis forms a more compact biofilm. These findings suggest that the optimized EIS-based method effectively monitors changes related to biofilms and serves as a promising tool for evaluation of new anti-biofilm agents, such as antibiotics, phages or antibodies. Full article
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23 pages, 1211 KB  
Review
Advancements and Applications of Split Technology in CRISPR/Cas12a: Transforming Molecular Diagnostics and Biosensing
by Saikarthik Jayakumar, Srinivasan Vengadassalapathy, Santhosh Venkadassalapathy, Sheela Durairajan, Radha Vijayaraj and Lakshmanan Govindan
Biosensors 2025, 15(9), 595; https://doi.org/10.3390/bios15090595 - 10 Sep 2025
Abstract
The rapid evolution of CRISPR technology has revolutionized molecular biology, and among the various systems, CRISPR/Cas12a stands out for its high specificity and efficient collateral cleavage activity. This review article focuses on the recent advancements and applications of split technology within the CRISPR/Cas12a [...] Read more.
The rapid evolution of CRISPR technology has revolutionized molecular biology, and among the various systems, CRISPR/Cas12a stands out for its high specificity and efficient collateral cleavage activity. This review article focuses on the recent advancements and applications of split technology within the CRISPR/Cas12a framework, highlighting its transformative role in molecular diagnostics and biosensing. Split technology innovatively divides functional nucleic acid components into modular segments that are activated by specific targets, significantly enhancing the specificity and sensitivity of biosensors. This design addresses the inherent limitations of traditional sensor systems, enabling the direct detection of ultrashort nucleic acids and improved discrimination of single-nucleotide variants, thereby facilitating the simultaneous detection of multiple biomolecules. The versatility of split-enabled biosensors extends beyond genetic testing, making them valuable tools in diagnostics, therapeutics, and environmental science. Despite challenges such as crRNA degradation and reassembly kinetics, ongoing research and engineering solutions continue to enhance the stability and performance of these systems. This review synthesizes the foundational principles, recent advancements, and potential applications of split technology while also identifying challenges and opportunities for future exploration. Ultimately, our insights provide a comprehensive resource to leverage the full potential of CRISPR/Cas12a-based split technology in advancing biosensing methodologies and clinical applications. Full article
(This article belongs to the Section Biosensor and Bioelectronic Devices)
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15 pages, 613 KB  
Article
Whole-Cell Bioreporter-Based Assay for Detecting Fungal-Derived β-Lactamase Inhibitors
by Raz Benou, Robert S. Marks, Alex Sivan, Esti Kramarsky-Winter, Karina Golberg and Ariel Kushmaro
Biosensors 2025, 15(9), 594; https://doi.org/10.3390/bios15090594 - 9 Sep 2025
Abstract
β-lactams are an important family of antibiotics that are prone to undergo resistance inhibition though the production of β-lactamases by some microorganisms. To combat this resistance and preserve the efficacy of β-lactam antibiotics, we developed a strategy for the discovery of such β-lactamase [...] Read more.
β-lactams are an important family of antibiotics that are prone to undergo resistance inhibition though the production of β-lactamases by some microorganisms. To combat this resistance and preserve the efficacy of β-lactam antibiotics, we developed a strategy for the discovery of such β-lactamase inhibitors. When combined with β-lactams, these inhibitors allow the antibiotics to be effective and prevent resistance. To date, the development of such combinatory drugs is limited due to the complexity of screening for new β-lactamase inhibitors. Therefore, to facilitate this development, it was essential to find sensitive assays to effectively screen for lactamase inhibitory compounds. To this end, a novel bioassay utilizing bioluminescent indicator bacteria as bioreporters was developed. The assay was first optimized using commercial antibiotics together with known β-lactamase inhibitors. Using this bioassay, we then screened for novel natural β-lactamase inhibitors derived from coral-associated fungi. We showed that the fungus Penicillium spinulosum, originating from the coral Pocillopora sp. from the Gulf of Aqaba Eilat, produced compounds with anti-β-lactamase activity. We further demonstrated that the bioreporter bacteria used here responded to the combined antibiotics and β-lactamase inhibitors in a concentration-dependent manner, indicating their usefulness for β-lactamase-inhibiting compound discovery. Future structural identification will promote the validation of this assay’s usefulness. Full article
(This article belongs to the Section Biosensor and Bioelectronic Devices)
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28 pages, 6575 KB  
Review
Role of Polymeric Stabilizing Agents as a Molecular Spacer in Gold Nanoparticle-Mediated FRET-Based Biosensing
by Atul Kumar Tiwari and Roger J. Narayan
Biosensors 2025, 15(9), 593; https://doi.org/10.3390/bios15090593 - 9 Sep 2025
Abstract
In FRET-based sensing, the interaction between the analytes and metal nanoparticles is significantly regulated by the physicochemical characteristics of the nanoparticles, such as their shape, size, zeta potential, surface-linked ligands, doping, pH of the medium, particle surface roughness, and lattice structure (atomic arrangements). [...] Read more.
In FRET-based sensing, the interaction between the analytes and metal nanoparticles is significantly regulated by the physicochemical characteristics of the nanoparticles, such as their shape, size, zeta potential, surface-linked ligands, doping, pH of the medium, particle surface roughness, and lattice structure (atomic arrangements). During the synthesis process, to avert the aggregation of gold nanoparticles (AuNPs), synthetic polymers (including polyethylene glycol, polyethyleneimine, and poly-N-vinylpyrrolidone) and natural polymers (such as chitosan, starch, gellan, welan, and κ-carrageenan) are frequently employed for stabilization. This stabilization is accomplished through mechanisms such as steric repulsion and electrostatic stabilization, which form a protective layer around AuNPs. These stabilizing polymers act as molecular spacers in nanoparticle-based FRET sensing, enabling the precise regulation of the molecular distance between the acceptor and donor fluorophore molecules. This regulation enhances the efficiency and sensitivity of FRET assays. By modifying the length and flexibility of the spacer polymer, researchers can adjust the spacing between fluorophores, ensuring effective energy transfer and the accurate detection of target molecules. However, there is a limited understanding of the role and broad application of these molecular spacers in nanoparticle-mediated FRET-based sensing of various analytes. Consequently, this review explores different fundamental aspects of FRET, polymeric stabilization of gold nanoparticles, and various polymeric spacers in FRET-based sensing, along with the recent advancements and challenges associated with this approach. Full article
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19 pages, 2679 KB  
Article
Development of a Multiplex Lateral Flow Immunoassay for the Detection of Antibiotics in Milk Utilizing Lyophilized Gold Nanoparticle Conjugates
by Ivan V. Maksin, Azhar Kuandykova, Darya I. Polyakova, Viktoriia A. Kesareva, Timofei A. Luzyanin, Vladislav S. Ivanov, Evgeniia I. Simonova, German A. Khunteev and Yuliya G. Kirillova
Biosensors 2025, 15(9), 592; https://doi.org/10.3390/bios15090592 - 9 Sep 2025
Abstract
Lateral flow immunoassays (LFAs) are widely recognized as a powerful and versatile analytical platform. Nevertheless, the development of multiplex formats remains a distinct challenge. The aim of this study was to develop a multiplex LFA using gold nanoparticles (GNPs) as a label, selected [...] Read more.
Lateral flow immunoassays (LFAs) are widely recognized as a powerful and versatile analytical platform. Nevertheless, the development of multiplex formats remains a distinct challenge. The aim of this study was to develop a multiplex LFA using gold nanoparticles (GNPs) as a label, selected for their ease of synthesis and functionalization with biomolecules. We provide practical recommendations regarding protein–hapten synthesis, membrane selection, application buffer composition, and methods to improve the long-term stability of the freeze-dried gold conjugate. The developed assay shows good tolerance to high-fat milk, stability at elevated temperatures, and promising sensitivity, with visual detection limits of 4–100 ng/mL for β-lactams, 1–10 ng/mL for tetracyclines, 50 ng/mL for streptomycin, and 0.3 ng/mL for chloramphenicol. Full article
(This article belongs to the Special Issue Immunosensors: Design and Applications)
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18 pages, 3215 KB  
Review
Review of Pulsation Signal Detection and Applications in Dynamic Photoacoustic Imaging
by Wenhan Zheng, Chuqin Huang and Jun Xia
Biosensors 2025, 15(9), 591; https://doi.org/10.3390/bios15090591 - 8 Sep 2025
Abstract
Pulsatile signal detection plays an important role in monitoring various physiological parameters, primarily heart rate and blood oxygen saturation. Their applications range from clinical settings to personal health and wellness monitoring. PPG (photoplethysmography) can provide non-invasive optical measurements to detect blood volume changes [...] Read more.
Pulsatile signal detection plays an important role in monitoring various physiological parameters, primarily heart rate and blood oxygen saturation. Their applications range from clinical settings to personal health and wellness monitoring. PPG (photoplethysmography) can provide non-invasive optical measurements to detect blood volume changes in peripheral tissues. Yet, it suffers from low spatial resolution to precisely detect the pulsatile signal originating over 2 mm in human tissue. Ultrasound (US) provides a deep detectable range compared to the pure optical method. However, its low contrast to red blood cells and cluster artifacts makes it only detect the indirect pulsation from the surrounding tissue of blood vessels. Recent advances in PA imaging show its capability to precisely measure pulsatile signals originating from blood vessels in deep regions (over 10 mm) and its potential to accurately record blood oxygen saturation with high spatial and temporal resolution. This review article summarizes studies on photoacoustic (PA) pulsatile signal monitoring, highlights the technical advances, and compares it against optical and ultrasonic approaches. Full article
(This article belongs to the Special Issue Advanced Optical Methods for Biosensing)
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44 pages, 8360 KB  
Systematic Review
Natural Iron Oxide Nanoparticles Produced by Aquatic Magnetotactic Bacteria as Ideal Nanozymes for Nano-Guided Biosensing Platforms—A Systematic Review
by Natalia Lorela Paul, Catalin Ovidiu Popa and Rodica Elena Ionescu
Biosensors 2025, 15(9), 590; https://doi.org/10.3390/bios15090590 - 8 Sep 2025
Abstract
In response to the ongoing challenges associated with natural enzymes, their high production costs, low stability and limited functionality; nanozymes have rapidly emerged as versatile alternative. Such nanocatalysts, based on nanomaterials and nanostructures, offer remarkable tunability of physicochemical properties and excellent durability, and [...] Read more.
In response to the ongoing challenges associated with natural enzymes, their high production costs, low stability and limited functionality; nanozymes have rapidly emerged as versatile alternative. Such nanocatalysts, based on nanomaterials and nanostructures, offer remarkable tunability of physicochemical properties and excellent durability, and adapt themselves effectively to the requirements of modern biotechnological applications. This review article aims to provide a comprehensive overview of recent advances in the use of naturally occurring iron oxide nanoparticles, produced by magnetotactic bacteria, and to highlight their emerging role as key elements in the development of the new generation of nano-guided biosensors. It provides a comprehensive and systematic analysis of publications in the Web of Science database between 2022 and August 2025, conducted in accordance with PRISMA guidelines. The aim was to assess the current state of the art and identify knowledge gaps in the exploration and application of magnetotactic bacteria as natural and sustainable sources in the design of next-generation biosensors. The natural nanoparticles, formed through biological processes, represent a unique and sustainable alternative to synthetic nanoparticles, offering naturally mimetic enzymatic activity, high biocompatibility, and exceptional stability. This approach opens up revolutionary perspectives in the field of biosensors, proposing a new class of functional materials, iron nanoparticles of biological origin, capable of fundamentally changing the performance, sustainability and reliability of future nanoenzymatic sensing platforms. Full article
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37 pages, 2546 KB  
Review
POC Sensor Systems and Artificial Intelligence—Where We Are Now and Where We Are Going?
by Prashanthi Kovur, Krishna M. Kovur, Dorsa Yahya Rayat and David S. Wishart
Biosensors 2025, 15(9), 589; https://doi.org/10.3390/bios15090589 - 8 Sep 2025
Abstract
Integration of machine learning (ML) and artificial intelligence (AI) into point-of-care (POC) sensor systems represents a transformative advancement in healthcare. This integration enables sophisticated data analysis and real-time decision-making in emergency and intensive care settings. AI and ML algorithms can process complex biomedical [...] Read more.
Integration of machine learning (ML) and artificial intelligence (AI) into point-of-care (POC) sensor systems represents a transformative advancement in healthcare. This integration enables sophisticated data analysis and real-time decision-making in emergency and intensive care settings. AI and ML algorithms can process complex biomedical data, improve diagnostic accuracy, and enable early disease detection for better patient outcomes. Predictive analytics in POC devices supports proactive healthcare by analyzing data to forecast health issues and facilitating early intervention and personalized treatment. This review covers the key areas of ML and AI integration in POC devices, including data analysis, pattern recognition, real-time decision support, predictive analytics, personalization, automation, and workflow optimization. Examples of current POC devices that use ML and AI include AI-powered blood glucose monitors, portable imaging devices, wearable cardiac monitors, AI-enhanced infectious disease detection, and smart wound care sensors are also discussed. The review further explores new directions for POC sensors and ML integration, including mental health monitoring, nutritional monitoring, metabolic health tracking, and decentralized clinical trials (DCTs). We also examined the impact of integrating ML and AI into POC devices on healthcare accessibility, efficiency, and patient outcomes. Full article
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17 pages, 2819 KB  
Article
Robust Pt/Au Composite Nanostructures for Abiotic Glucose Sensing
by Asghar Niyazi, Ashley Linden and Mirella Di Lorenzo
Biosensors 2025, 15(9), 588; https://doi.org/10.3390/bios15090588 - 8 Sep 2025
Abstract
Effective glucose monitoring is paramount for patients with diabetes to effectively manage their condition and prevent health complications. Electrochemical sensors for glucose monitoring have key advantages over other systems, including cost-effectiveness, miniaturisation and portability, enabling the design of compact and wearable devices. Typically, [...] Read more.
Effective glucose monitoring is paramount for patients with diabetes to effectively manage their condition and prevent health complications. Electrochemical sensors for glucose monitoring have key advantages over other systems, including cost-effectiveness, miniaturisation and portability, enabling the design of compact and wearable devices. Typically, enzymes are used in these sensors, with the limitations of poor stability and high cost. In alternative, this study reports the development of a gold and platinum composite nanostructured electrode and its testing as an abiotic (enzyme-free) electrocatalyst for glucose oxidation. The electrode consists of a film of highly porous gold electrodeposited onto gold-plated electrodes on a printed circuit board (PCB), which is coated with polyaniline decorated with platinum nanoparticles. The resulting nanocomposite structure shows a sensitivity towards glucose as high as 95.12 ± 2.54 µA mM−1 cm−2, nearly twice that of the highly porous gold electrodes, and excellent stability in synthetic interstitial fluid over extended testing, thus demonstrating robustness. Accordingly, this study lays the groundwork for the next generation of durable, selective, and affordable abiotic glucose biosensors. Full article
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50 pages, 4023 KB  
Review
Organic Bioelectronics: Diversity of Electronics Along with Biosciences
by Syed Abdul Moiz, Mohammed Saleh Alshaikh and Ahmed N. M. Alahmadi
Biosensors 2025, 15(9), 587; https://doi.org/10.3390/bios15090587 - 7 Sep 2025
Viewed by 340
Abstract
This review article provides an introductory overview of organic bioelectronics, focusing on the creation of electrical devices that use specialized carbon-based semiconducting materials to interact successfully with biological processes. These organic materials demonstrate flexibility, biocompatibility, and the capacity to carry both electrical and [...] Read more.
This review article provides an introductory overview of organic bioelectronics, focusing on the creation of electrical devices that use specialized carbon-based semiconducting materials to interact successfully with biological processes. These organic materials demonstrate flexibility, biocompatibility, and the capacity to carry both electrical and ionic impulses, making them an ideal choice for connecting human tissue with electronic technology. The review study examines diverse materials, such as the conductive polymers Poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) and Polyaniline (PANI), along with critical devices like organic electrochemical transistors (OECTs), which are exceptionally efficient for sensitive biosensing applications. Significant applications include implanted neural interfaces for the brain and nerves, wearable health monitoring, tissue engineering scaffolds that facilitate tissue repair, and sophisticated drug delivery systems. The review acknowledges current challenges, including long-term stability and safety, while envisioning a future where these technologies revolutionize healthcare, human–machine interaction, and environmental monitoring via continuous multidisciplinary innovation. Full article
(This article belongs to the Section Biosensor and Bioelectronic Devices)
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40 pages, 3625 KB  
Review
Graphene-Based Biosensors: Enabling the Next Generation of Diagnostic Technologies—A Review
by John Paolo Ramoso, Manoochehr Rasekh and Wamadeva Balachandran
Biosensors 2025, 15(9), 586; https://doi.org/10.3390/bios15090586 - 6 Sep 2025
Viewed by 340
Abstract
Graphene, a two-dimensional carbon material with a hexagonal lattice structure, possesses remarkable properties. Exceptional electrical conductivity, mechanical strength, and high surface area that make it a powerful platform for biosensing applications. Its sp2-hybridised network facilitates efficient electron mobility and enables diverse [...] Read more.
Graphene, a two-dimensional carbon material with a hexagonal lattice structure, possesses remarkable properties. Exceptional electrical conductivity, mechanical strength, and high surface area that make it a powerful platform for biosensing applications. Its sp2-hybridised network facilitates efficient electron mobility and enables diverse surface functionalisation through bio-interfacing. This review highlights the core detection mechanisms in graphene-based biosensors. Optical sensing techniques, such as surface plasmon resonance (SPR) and surface-enhanced Raman scattering (SERS), benefit significantly from graphene’s strong light–matter interaction, which enhances signal sensitivity. Although graphene itself lacks intrinsic piezoelectricity, its integration with piezoelectric substrates can augment the performance of piezoelectric biosensors. In electrochemical sensing, graphene-based electrodes support rapid electron transfer, enabling fast response times across a range of techniques, including impedance spectroscopy, amperometry, and voltammetry. Graphene field-effect transistors (GFETs), which leverage graphene’s high carrier mobility, offer real-time, label-free, and highly sensitive detection of biomolecules. In addition, the review also explores multiplexed detection strategies vital for point-of-care diagnostics. Graphene’s nanoscale dimensions and tunable surface chemistry facilitate both array-based configurations and the simultaneous detection of multiple biomarkers. This adaptability makes graphene an ideal material for compact, scalable, and accurate biosensor platforms. Continued advancements in graphene biofunctionalisation, sensing modalities, and integrated multiplexing are driving the development of next-generation biosensors with superior sensitivity, selectivity, and diagnostic reliability. Full article
(This article belongs to the Special Issue Novel Graphene-Based Biosensors for Biomedical Applications)
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26 pages, 6690 KB  
Article
Head-Specific Spatial Spectra of Electroencephalography Explained: A Sphara and BEM Investigation
by Uwe Graichen, Sascha Klee, Patrique Fiedler, Lydia Hofmann and Jens Haueisen
Biosensors 2025, 15(9), 585; https://doi.org/10.3390/bios15090585 - 6 Sep 2025
Viewed by 120
Abstract
Electroencephalography (EEG) is a non-invasive biosensing platform with a spatial-frequency content that is of significant relevance for a multitude of aspects in the neurosciences, ranging from optimal spatial sampling of the EEG to the design of spatial filters and source reconstruction. In the [...] Read more.
Electroencephalography (EEG) is a non-invasive biosensing platform with a spatial-frequency content that is of significant relevance for a multitude of aspects in the neurosciences, ranging from optimal spatial sampling of the EEG to the design of spatial filters and source reconstruction. In the past, simplified spherical head models had to be used for this analysis. We propose a method for spatial frequency analysis in EEG for realistically shaped volume conductors, and we exemplify our method with a five-compartment Boundary Element Method (BEM) model of the head. We employ the recently developed technique for spatial harmonic analysis (Sphara), which allows for spatial Fourier analysis on arbitrarily shaped surfaces in space. We first validate and compare Sphara with the established method for spatial Fourier analysis on spherical surfaces, discrete spherical harmonics, using a spherical volume conductor. We provide uncertainty limits for Sphara. We derive relationships between the signal-to-noise ratio (SNR) and the required spatial sampling of the EEG. Our results demonstrate that conventional 10–20 sampling might misestimate EEG power by up to 50%, and even 64 electrodes might misestimate EEG power by up to 15%. Our results also provide insights into the targeting problem of transcranial electric stimulation. Full article
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30 pages, 6580 KB  
Article
Advanced Nanomaterial-Based Electrochemical Biosensing of Loop-Mediated Isothermal Amplification Products
by Ana Kuprešanin, Marija Pavlović, Ljiljana Šašić Zorić, Milinko Perić, Stefan Jarić, Teodora Knežić, Ljiljana Janjušević, Zorica Novaković, Marko Radović, Mila Djisalov, Nikola Kanas, Jovana Paskaš and Zoran Pavlović
Biosensors 2025, 15(9), 584; https://doi.org/10.3390/bios15090584 - 5 Sep 2025
Viewed by 440
Abstract
The rapid and sensitive detection of regulatory elements within transgenic constructs of genetically modified organisms (GMOs) is essential for effective monitoring and control of their distribution. In this study, we present several innovative electrochemical biosensing platforms for the detection of regulatory sequences in [...] Read more.
The rapid and sensitive detection of regulatory elements within transgenic constructs of genetically modified organisms (GMOs) is essential for effective monitoring and control of their distribution. In this study, we present several innovative electrochemical biosensing platforms for the detection of regulatory sequences in genetically modified (GM) plants, combining the loop-mediated isothermal amplification (LAMP) method with electrodes functionalized by two-dimensional (2D) nanomaterials. The sensor design exploits the high surface area and excellent conductivity of reduced graphene oxide, Ti3C2Tx, and molybdenum disulfide (MoS2) to enhance signal transduction. Furthermore, we used a “green synthesis” method for Ti3C2Tx preparation that eliminates the use of hazardous hydrofluoric acid (HF) and hydrochloric acid (HCl), providing a safer and more sustainable approach for nanomaterial production. Within this framework, the performance of various custom-fabricated electrodes, including laser-patterned gold leaf films, physical vapor deposition (PVD)-deposited gold electrodes, and screen-printed gold electrodes, is evaluated and compared with commercial screen-printed gold electrodes. Additionally, gold and carbon electrodes were electrochemically covered by gold nanoparticles (AuNPs), and their properties were compared. Several electrochemical methods were used during the DNA detection, and their importance and differences in excitation signal were highlighted. Electrochemical properties, sensitivity, selectivity, and reproducibility are characterized for each electrode type to assess the influence of fabrication methods and material composition on sensor performance. The developed biosensing systems exhibit high sensitivity, specificity, and rapid response, highlighting their potential as practical tools for on-site GMO screening and regulatory compliance monitoring. This work advances electrochemical nucleic acid detection by integrating environmentally-friendly nanomaterial synthesis with robust biosensing technology. Full article
(This article belongs to the Section Biosensor Materials)
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14 pages, 1621 KB  
Article
A Bluetooth-Enabled Electrochemical Platform Based on Saccharomyces cerevisiae Yeast Cells for Copper Detection
by Ehtisham Wahid, Ohiemi Benjamin Ocheja, Antonello Longo, Enrico Marsili, Massimo Trotta, Matteo Grattieri, Cataldo Guaragnella and Nicoletta Guaragnella
Biosensors 2025, 15(9), 583; https://doi.org/10.3390/bios15090583 - 5 Sep 2025
Viewed by 1253
Abstract
Copper contamination in the environment poses significant risks to both soil and human health, making the need for reliable monitoring methods crucial. In this study, we report the use of the EmStat Pico module as potentiostat to develop a portable electrochemical biosensor for [...] Read more.
Copper contamination in the environment poses significant risks to both soil and human health, making the need for reliable monitoring methods crucial. In this study, we report the use of the EmStat Pico module as potentiostat to develop a portable electrochemical biosensor for copper detection, utilizing yeast Saccharomyces cerevisiae cells immobilized on a polydopamine (PDA)-coated screen-printed electrode (SPE). By optimizing the sensor design with a horizontal assembly and the volume reduction in the electrolyte solution, we achieved a 10-fold increase in current density with higher range of copper concentrations (0–300 µM CuSO4) compared to traditional (or previous) vertical dipping setups. Additionally, the use of genetically engineered copper-responsive yeast cells further improved sensor performance, with the recombinant strain showing a 1.7-fold increase in current density over the wild-type strain. The biosensor demonstrated excellent reproducibility (R2 > 0.95) and linearity over a broad range of copper concentrations, making it suitable for precise quantitative analysis. To further enhance portability and usability, a Bluetooth-enabled electrochemical platform was integrated with a web application for real-time data analysis, enabling on-site monitoring and providing a reliable, cost-effective tool for copper detection in real world settings. This system offers a promising solution for addressing the growing need for efficient environmental monitoring, especially in agriculture. Full article
(This article belongs to the Special Issue Sensors for Environmental Monitoring and Food Safety—2nd Edition)
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14 pages, 3684 KB  
Article
Accuracy Enhancement in Refractive Index Sensing via Full-Spectrum Machine Learning Modeling
by Majid Aalizadeh, Chinmay Raut, Morteza Azmoudeh Afshar, Ali Tabartehfarahani and Xudong Fan
Biosensors 2025, 15(9), 582; https://doi.org/10.3390/bios15090582 - 5 Sep 2025
Viewed by 227
Abstract
We present a full-spectrum machine learning framework for refractive index sensing using simulated absorption spectra from meta-grating structures composed of titanium or silicon nanorods under TE and TM polarizations. Linear regression was applied to 80 principal components extracted from each spectrum, and model [...] Read more.
We present a full-spectrum machine learning framework for refractive index sensing using simulated absorption spectra from meta-grating structures composed of titanium or silicon nanorods under TE and TM polarizations. Linear regression was applied to 80 principal components extracted from each spectrum, and model performance was assessed using five-fold cross-validation, simulating real-world biosensing scenarios where unknown patient samples are predicted based on standard calibration data. Titanium-based structures, dominated by broadband intensity changes, yielded the lowest mean squared errors and the highest accuracy improvements—up to an 8128-fold reduction compared to the best single-feature model. In contrast, silicon-based structures, governed by narrow resonances, showed more modest gains due to spectral nonlinearity that limits the effectiveness of global linear models. We also show that even the best single-wavelength predictor is identified through data-driven analysis, not visual selection, highlighting the value of automated feature preselection. These findings demonstrate that spectral shape plays a key role in modeling performance and that full-spectrum linear approaches are especially effective for intensity-modulated index sensors. Full article
(This article belongs to the Section Optical and Photonic Biosensors)
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16 pages, 3627 KB  
Article
In Vivo Study on the Safe Use of a Novel Intraoperative Sensing Tool for Tissue Stiffness Assessment in Endoscopic Surgery
by Georgios Violakis, Pantelis Antonakis, Emmanouil Kritsotakis, Theodoros Kozonis, Leonidas Chardalias, Apostolos Papalois, Georgios Agrogiannis, Effrosyni Kampouroglou, Nikolaos Vardakis, Stylianos Kostakis, Eleni Athanasaki, Zhenyu Zhang, Martin Angelmahr, Manousos Konstadoulakis and Panagiotis Polygerinos
Biosensors 2025, 15(9), 581; https://doi.org/10.3390/bios15090581 - 5 Sep 2025
Viewed by 239
Abstract
A novel endoscopic palpation tool (EPT), designed for tactile and stiffness sensing using fiber Bragg gratings (FBGs) was evaluated in a surgical environment for intraoperative safety and effectiveness. The EPT consisted of four FBGs arranged in a cross pattern and embedded within an [...] Read more.
A novel endoscopic palpation tool (EPT), designed for tactile and stiffness sensing using fiber Bragg gratings (FBGs) was evaluated in a surgical environment for intraoperative safety and effectiveness. The EPT consisted of four FBGs arranged in a cross pattern and embedded within an elastic, hollow, silicone hemispherical dome designed to deform upon contact with soft tissue. The EPT was employed to scan both in vivo and ex vivo tissue samples. Monitoring of porcine vital signs during minimally invasive and open surgical procedures showed no significant changes during use of the EPT. Perioperative blood tests including inflammatory markers and liver and renal function studies were unremarkable. Histopathological analyses of tissues involved (liver, spleen, bowel, and abdominal wall) showed no evidence of inflammation, necrosis, or tissue damage, confirming the device’s biocompatibility. To the best of our knowledge, this is the first study reporting in vivo stiffness measurements using an FBG-based EPT. The probe successfully distinguished between soft and hard tissue regions’ relative stiffness. Furthermore, successive measurements on liver samples demonstrated the device’s ability to generate stiffness maps, enabling clear visualization of spatial variation in tissue stiffness. Full article
(This article belongs to the Section Optical and Photonic Biosensors)
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32 pages, 5916 KB  
Review
Advances and Innovations in Conjugated Polymer Fluorescent Sensors for Environmental and Biological Detection
by Viet-Duc Phung and Vinh Van Tran
Biosensors 2025, 15(9), 580; https://doi.org/10.3390/bios15090580 - 4 Sep 2025
Viewed by 269
Abstract
Thanks to their multiple outstanding features—such as high fluorescence quantum yield, good photostability, and excellent sensitivity—conjugated polymers (CPs) have emerged as a pioneering class of fluorescent materials for sensing applications, particularly in environmental and biological fields, for the detection of a wide range [...] Read more.
Thanks to their multiple outstanding features—such as high fluorescence quantum yield, good photostability, and excellent sensitivity—conjugated polymers (CPs) have emerged as a pioneering class of fluorescent materials for sensing applications, particularly in environmental and biological fields, for the detection of a wide range of environmental pollutants and bioactive compounds. The presence of delocalized π-electrons in the CP backbone significantly enhances sensing performance through a unique phenomenon known as the “molecular wire effect.” As a result, CP-based fluorescent sensors have been extensively developed and employed as exceptional tools for monitoring various analytes in environmental and biological contexts. A deep understanding of their unique properties, fabrication techniques, and recent innovations is essential for guiding the strategic development of advanced CP-based fluorescent sensors, particularly for future point-of-care applications. This study presents a critical review of the key characteristics of fluorescent sensors and highlights several common types of conjugated polymers (CPs) used in their design and fabrication. It summarizes and discusses the main sensing mechanisms, state-of-the-art applications, and recent innovations of CP-based fluorescent sensors for detecting target compounds in environmental and biological fields. Furthermore, potential strategies and future perspectives for designing and developing high-performance CP-based fluorescent sensors are emphasized. By consolidating current scientific evidence, this review aims to support the advancement of highly sensitive fluorescent sensors based on various CP nanoparticles for environmental and biological applications. Full article
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17 pages, 1568 KB  
Article
Cell-Free DNA Versus Circulating Tumor Cells: A Pilot Study of Alpha-Fetoprotein Analysis for Diagnosis and Treatment Monitoring in Hepatocellular Carcinoma
by Ga Young Moon, Hyun Sung Park, Ha Neul Kim, Hei-Gwon Choi, Yonghan Han, Hyuk Soo Eun, Tae Hee Lee and Jiyoon Bu
Biosensors 2025, 15(9), 579; https://doi.org/10.3390/bios15090579 - 4 Sep 2025
Viewed by 314
Abstract
Serum alpha-fetoprotein (AFP) is widely used for hepatocellular carcinoma (HCC) management, yet its limited sensitivity and specificity restrict diagnostic and prognostic utility. In this study, we explore the clinical potential of AFP quantification from cell-free DNA (cfDNA) and circulating tumor cells (CTCs) using [...] Read more.
Serum alpha-fetoprotein (AFP) is widely used for hepatocellular carcinoma (HCC) management, yet its limited sensitivity and specificity restrict diagnostic and prognostic utility. In this study, we explore the clinical potential of AFP quantification from cell-free DNA (cfDNA) and circulating tumor cells (CTCs) using a novel bead-based liquid biopsy platform. Following isolation, AFP abundance in cfDNA was quantified by qPCR, while AFP protein expression in CTCs was assessed via immunohistochemistry. Compared to serum AFP, cfDNA-derived AFP demonstrated significantly greater diagnostic accuracy in distinguishing HCC patients from non-cancerous individuals (p < 0.0001, AUC = 0.998), while AFP+ CTCs showed high specificity. Post-treatment changes in AFP levels from cfDNA and CTCs were significantly associated with therapeutic response and overall survival, outperforming conventional serum AFP. Longitudinal monitoring further revealed that cfDNA AFP levels reliably captured recurrence events prior to clinical diagnosis. Moreover, a combined metric integrating AFP levels from cfDNA and CTCs significantly improved response stratification (AUC = 0.89), outperforming individual biomarkers. This pilot study highlights the potential of multimodal AFP profiling through cfDNA and CTCs as a promising, non-invasive approach for enhancing diagnosis, prognosis, and treatment monitoring in HCC, with direct implications for personalized therapeutic strategies. Full article
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22 pages, 4751 KB  
Article
Motion Artifacts (MA) At-Rest in Measured Arterial Pulse Signals: Time-Varying Amplitude in Each Harmonic and Non-Flat Harmonic-MA-Coupled Baseline
by MD Mahfuzur Rahman, Mamun Hasan and Zhili Hao
Biosensors 2025, 15(9), 578; https://doi.org/10.3390/bios15090578 - 4 Sep 2025
Viewed by 227
Abstract
Motion artifacts (MA) cause great variability in a measured arterial pulse signal, and treatment of MA solely as a baseline drift (BD) fails to eliminate its effect on the measured signal. This paper presents a study on the effect of MA at rest [...] Read more.
Motion artifacts (MA) cause great variability in a measured arterial pulse signal, and treatment of MA solely as a baseline drift (BD) fails to eliminate its effect on the measured signal. This paper presents a study on the effect of MA at rest (<0.7 Hz) on measured arterial pulse signals using a microfluidic-based tactile sensor. By taking full account of the dynamic behavior of the transmission path from the true pulse signal in an artery to a measured pulse signal at the sensor, the tissue-contact-sensor (TCS) stack, an analytical model of MA in a measured pulse signal is developed. In this model, the TCS stack is treated as a 1DOF system for its dynamic behavior; MA is quantified as the displacement (i.e., BD) and time-varying system parameters (TVSP) of the TCS stack. The mathematical expression of MA in a measured pulse signal reveals that while BD remains as low-frequency additive noise, TVSP causes time-varying harmonics in a measured pulse signal. Further time-frequency analysis (TFA) of measured pulse signals validates the existence of TVSP and, for the first time, reveals its effect on a measured pulse signal: time-varying amplitude in each harmonic and non-flat harmonic-MA-coupled baseline. Full article
(This article belongs to the Special Issue Biosensors Based on Microfluidic Devices—2nd Edition)
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17 pages, 1545 KB  
Article
Portable Point-of-Care Device for Dual Detection of Glucose-6-Phosphate Dehydrogenase Deficiency and Hemoglobin in Low-Resource Settings
by Rehab Osman Taha, Napaporn Youngvises, Runtikan Pochairach, Papichaya Phompradit and Kesara Na-Bangchang
Biosensors 2025, 15(9), 577; https://doi.org/10.3390/bios15090577 - 3 Sep 2025
Viewed by 340
Abstract
Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a common enzymopathy with significant clinical implications, particularly in malaria-endemic regions and in the management of neonatal hyperbilirubinemia. Timely and accurate detection of G6PD deficiency is critical to prevent life-threatening hemolytic events following oxidative drug administration. This study [...] Read more.
Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a common enzymopathy with significant clinical implications, particularly in malaria-endemic regions and in the management of neonatal hyperbilirubinemia. Timely and accurate detection of G6PD deficiency is critical to prevent life-threatening hemolytic events following oxidative drug administration. This study evaluated the MyG6PD device, a quantitative point-of-care (PoC) tool, for the assessment of hemoglobin concentration and G6PD enzyme activity. Analytical performance was benchmarked against laboratory spectrophotometry and the STANDARD G6PD Analyzer™ (SD Biosensor; Suwon-si, Republic of Korea). MyG6PD demonstrated excellent linearity (R2 ≥ 0.99), accuracy (bias < ±15%), and precision (CV < 15%) across normal, intermediate, and deficient activity ranges, including heterozygous females with intermediate phenotypes. The device’s compact, battery-operated design, rapid turnaround, and minimal training requirements support its use in decentralized and resource-limited settings. Furthermore, cost-effective consumables and robust detection of intermediate activity highlight its potential for large-scale deployment. Overall, MyG6PD provides a reliable, accessible, and clinically actionable solution for urgent G6PD deficiency screening, enabling safer administration of oxidative therapies and improving patient outcomes in high-risk populations. Full article
(This article belongs to the Section Biosensors and Healthcare)
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17 pages, 2747 KB  
Article
Flexible and Stretchable Microneedle Electrode Arrays by Soft Lithography for Continuous Monitoring of Glucose
by Yong-Ho Choi, Honglin Piao, Jia Lee, Jaehyun Kim, Heon-Jin Choi and Dahl-Young Khang
Biosensors 2025, 15(9), 576; https://doi.org/10.3390/bios15090576 - 2 Sep 2025
Viewed by 402
Abstract
Continuous monitoring of glucose (CGM) level is of utmost importance to diabetic patients, especially with no or minimal pain. Microneedle arrays with desired electrode patterns have been fabricated by soft lithographic molding, and the patterned electrodes were formed via shadow evaporation through a [...] Read more.
Continuous monitoring of glucose (CGM) level is of utmost importance to diabetic patients, especially with no or minimal pain. Microneedle arrays with desired electrode patterns have been fabricated by soft lithographic molding, and the patterned electrodes were formed via shadow evaporation through a shadow mask that was made from a modified molding technique. With immobilization of glucose oxidase (GOx), the microneedle electrode arrays (MEAs) have been successfully employed for the in vitro CGM using impedance spectroscopy. The fabricated MEAs could monitor the varying glucose level continuously for up to ~10 days. Similar processes have been applied for the fabrication of stretchable MEAs, which can conform to complex curvilinear surfaces. The simple and low-cost fabrication of MEAs, either in flexible or stretchable forms, may find various applications in wearable health monitoring techniques. Full article
(This article belongs to the Special Issue Recent Advances in Glucose Biosensors)
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22 pages, 3921 KB  
Article
A Sensitive Electrochemical Cholinesterase-Inhibiting Biosensor for Organophosphorus Pesticides Based on Ti3C2TX MXene Quantum Dots
by Nisha Makani, Jett Wu, Jose Florentino, Cecilia F. Chafin, Bhoj Gautam, Shirley Chao and Shubo Han
Biosensors 2025, 15(9), 575; https://doi.org/10.3390/bios15090575 - 2 Sep 2025
Viewed by 429
Abstract
Organophosphorus pesticides (OPs) pose significant environmental and health risks due to their widespread use and toxicity, primarily by inhibiting acetylcholinesterase. Traditional detection methods are often slow and costly, highlighting the urgent need for advanced, sensitive, and accessible technologies. This study developed a highly [...] Read more.
Organophosphorus pesticides (OPs) pose significant environmental and health risks due to their widespread use and toxicity, primarily by inhibiting acetylcholinesterase. Traditional detection methods are often slow and costly, highlighting the urgent need for advanced, sensitive, and accessible technologies. This study developed a highly sensitive electrochemical cholinesterase-inhibiting biosensor for OP pesticides, utilizing Ti3C2Tx MXene Quantum Dots (MQDs), which was synthesized via a hydrothermal method. The biosensor’s performance was characterized using electrochemical impedance spectroscopy, differential pulse voltammetry (DPV), and cyclic voltammetry. DPV proved to be the optimal technique, exhibiting an ultralow detection limit of 1 × 10−17 M and a wide linear range (10−14–10−8 M) for chlorpyrifos (a model OP) with an estimated inhibition constant of 62 nM. The biosensor demonstrated high selectivity for OPs (chlorpyrifos, acephate, glyphosate) over a non-target pyrethroid (permethrin), confirmed by distinct electrochemical signatures and compared to in vitro cholinergic activity assays in bean beetle homogenates. The enhanced performance is attributed to the high surface-to-volume ratio, quantum confinement effects, and superior conductivity of the MQDs, as well as the robust enzyme immobilization facilitated by glutaraldehyde cross-linking and a chitosan matrix. This work presents a promising platform for rapid, sensitive, and selective detection of OP pesticides, with potential applications in environmental monitoring and public health protection. Full article
(This article belongs to the Section Biosensor Materials)
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33 pages, 4561 KB  
Review
Smartphone-Integrated Electrochemical Devices for Contaminant Monitoring in Agriculture and Food: A Review
by Sumeyra Savas and Seyed Mohammad Taghi Gharibzahedi
Biosensors 2025, 15(9), 574; https://doi.org/10.3390/bios15090574 - 2 Sep 2025
Viewed by 645
Abstract
Recent progress in microfluidic technologies has led to the development of compact and highly efficient electrochemical platforms, including lab-on-a-chip (LoC) systems, that integrate multiple testing functions into a single, portable device. Combined with smartphone-based electrochemical devices, these systems enable rapid and accurate on-site [...] Read more.
Recent progress in microfluidic technologies has led to the development of compact and highly efficient electrochemical platforms, including lab-on-a-chip (LoC) systems, that integrate multiple testing functions into a single, portable device. Combined with smartphone-based electrochemical devices, these systems enable rapid and accurate on-site detection of food contaminants, including pesticides, heavy metals, pathogens, and chemical additives at farms, markets, and processing facilities, significantly reducing the need for traditional laboratories. Smartphones improve the performance of these platforms by providing computational power, wireless connectivity, and high-resolution imaging, making them ideal for in-field food safety testing with minimal sample and reagent requirements. At the core of these systems are electrochemical biosensors, which convert specific biochemical reactions into electrical signals, ensuring highly sensitive and selective detection. Advanced nanomaterials and integration with Internet of Things (IoT) technologies have further improved performance, delivering cost-effective, user-friendly food monitoring solutions that meet regulatory safety and quality standards. Analytical techniques such as voltammetry, amperometry, and impedance spectroscopy increase accuracy even in complex food samples. Moreover, low-cost engineering, artificial intelligence (AI), and nanotechnology enhance the sensitivity, affordability, and data analysis capabilities of smartphone-integrated electrochemical devices, facilitating their deployment for on-site monitoring of food and agricultural contaminants. This review explains how these technologies address global food safety challenges through rapid, reliable, and portable detection, supporting food quality, sustainability, and public health. Full article
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23 pages, 3035 KB  
Review
SERS-Driven Evolution of Lateral and Vertical Flow Assays in Medical Diagnostics
by Boyou Heo and Ho Sang Jung
Biosensors 2025, 15(9), 573; https://doi.org/10.3390/bios15090573 - 1 Sep 2025
Viewed by 512
Abstract
Surface-enhanced Raman scattering (SERS) has emerged as a powerful signal amplification strategy to address the inherent limitations of conventional flow-based diagnostic methods such as lateral flow analysis (LFA) and vertical flow analysis (VFA). By incorporating SERS-active nanostructures into these platforms, SERS-integrated LFA and [...] Read more.
Surface-enhanced Raman scattering (SERS) has emerged as a powerful signal amplification strategy to address the inherent limitations of conventional flow-based diagnostic methods such as lateral flow analysis (LFA) and vertical flow analysis (VFA). By incorporating SERS-active nanostructures into these platforms, SERS-integrated LFA and VFA systems have significantly improved sensitivity, specificity, and multiplexing performance while maintaining the simplicity and portability of conventional approaches. In this review, we summarize recent advances in SERS-enhanced flow-based diagnostics with a focus on exogenous and endogenous disease detection. Exogenous targets include viral antigens, bacterial pathogens, and foodborne contaminants such as mycotoxins and antibiotic residues. Endogenous applications include therapeutic drug monitoring, inflammation profiling, cancer biomarker detection, and exosome-based molecular subtyping. We highlight the structural differences between LFA and VFA approaches and their impact on analytical performance, and explore the advantages of SERS-integrated platforms for rapid and multiplexed detection in complex biological matrices. Finally, we provide an overview of key technical challenges, such as signal reproducibility, matrix interference, and device integration, and discuss future directions for clinical implementation of SERS-based flow diagnostics in point-of-care settings. Full article
(This article belongs to the Special Issue Nano/Micro Biosensors for Biomedical Applications (2nd Edition))
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13 pages, 2327 KB  
Communication
Quantitative IC50 Analysis of Puromycin-Induced Cytotoxicity in NIH/3T3 Cells Using a Multi-Well Array Impedance Biosensor
by Seok-kyu Kim, SuGwon Nam and Moongyu Jang
Biosensors 2025, 15(9), 572; https://doi.org/10.3390/bios15090572 - 1 Sep 2025
Viewed by 425
Abstract
ECIS-based impedance biosensors have been extensively studied in various fields including cancer research, microbiology, and immunology. However, most studies have primarily focused on monitoring cellular behavior through impedance changes, with relatively less emphasis on interpreting the biological significance of impedance signals. In this [...] Read more.
ECIS-based impedance biosensors have been extensively studied in various fields including cancer research, microbiology, and immunology. However, most studies have primarily focused on monitoring cellular behavior through impedance changes, with relatively less emphasis on interpreting the biological significance of impedance signals. In this study, we employed a multi-well array impedance biosensor to conduct IC50 (half-maximal inhibitory concentration) analysis, a widely used metric for evaluating drug efficacy and toxicity in biological and pharmacological research. Specifically, we assessed the IC50 values of puromycin, an aminonucleoside antibiotic known to inhibit protein synthesis. NIH/3T3 fibroblasts were exposed to various concentrations of puromycin, and real-time impedance monitoring was performed. Cell viability was assessed, and the IC50 value of puromycin for NIH/3T3 cells was determined to be 3.96 µM using capacitance-based impedance analysis. Our findings demonstrate that the multi-well array impedance biosensor provides a rapid and quantitative method for drug toxicity evaluation, offering a valuable platform for drug screening and biocompatibility assessment. Full article
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29 pages, 3451 KB  
Review
Deep Learning-Enhanced Nanozyme-Based Biosensors for Next-Generation Medical Diagnostics
by Seungah Lee, Nayra A. M. Moussa and Seong Ho Kang
Biosensors 2025, 15(9), 571; https://doi.org/10.3390/bios15090571 - 1 Sep 2025
Viewed by 508
Abstract
The integration of deep learning (DL) and nanozyme-based biosensing has emerged as a transformative strategy for next-generation medical diagnostics. This review explores how DL architectures enhance nanozyme design, functional optimization, and predictive modeling by elucidating catalytic mechanisms such as dual-atom active sites and [...] Read more.
The integration of deep learning (DL) and nanozyme-based biosensing has emerged as a transformative strategy for next-generation medical diagnostics. This review explores how DL architectures enhance nanozyme design, functional optimization, and predictive modeling by elucidating catalytic mechanisms such as dual-atom active sites and substrate-surface interactions. Key applications include disease biomarker detection, medical imaging enhancement, and point-of-care diagnostics aligned with the ASSURED criteria. In clinical contexts, advances such as wearable biosensors and smart diagnostic platforms leverage DL for real-time signal processing, pattern recognition, and adaptive decision-making. Despite significant progress, challenges remain—particularly the need for standardized biomedical datasets, improved model robustness across diverse populations, and the clinical translation of artificial intelligence (AI)-enhanced nanozyme systems. Future directions include integration with the Internet of Medical Things, personalized medicine frameworks, and sustainable sensor development. The convergence of nanozymes and DL offers unprecedented opportunities to advance intelligent biosensing and reshape precision diagnostics in healthcare. Full article
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