Herein, we present a broad SERS-based biosensing platform for multi-target detection via indirect immunoassay. The system employed antibody-functionalized AuNPs linked with an indicative Raman reporter, which were subsequently amplified by a silver-coated porous silicon microarray, employed as the SERS transducer. Under optimized physical parameters and operational conditions, while using a portable Raman device, the bioassay depicted low limits of detection (5, 5, and 4 CFU/mL for Escherichia coli, Staphylococcus aureus, and Bacillus cereus, respectively) spanning the linear range of 101 to 105 CFU/mL. The selectivity of the bioassay was validated against common interfering enteropathogenic species with insignificant cross-reactivity. Subsequently, various food samples, including irrigation water, lettuce, rice, chicken, and milk, were optically assessed while demonstrating recovery rates between 81.4% and 107.1%, with RSD below 8.5% across all studied conditions. Our findings highlight the robustness and applicability of the presented multiplex SERS platform for rapid and accurate detection of bacterial contaminants in complex food systems.
{"title":"Multiplex pathogenic bacteria detection in food systems using gold-nanoparticles coupled with porous silicon microarray used as a SERS-transducer","authors":"Divagar Muthukumar , Omer Tamari , Narsingh R. Nirala , Rohit Kumar Singh , Moshe Shemesh , Giorgi Shtenberg","doi":"10.1016/j.snr.2025.100433","DOIUrl":"10.1016/j.snr.2025.100433","url":null,"abstract":"<div><div>Herein, we present a broad SERS-based biosensing platform for multi-target detection via indirect immunoassay. The system employed antibody-functionalized AuNPs linked with an indicative Raman reporter, which were subsequently amplified by a silver-coated porous silicon microarray, employed as the SERS transducer. Under optimized physical parameters and operational conditions, while using a portable Raman device, the bioassay depicted low limits of detection (5, 5, and 4 CFU/mL for <em>Escherichia coli, Staphylococcus aureus,</em> and <em>Bacillus cereus</em>, respectively) spanning the linear range of 10<sup>1</sup> to 10<sup>5</sup> CFU/mL. The selectivity of the bioassay was validated against common interfering enteropathogenic species with insignificant cross-reactivity. Subsequently, various food samples, including irrigation water, lettuce, rice, chicken, and milk, were optically assessed while demonstrating recovery rates between 81.4% and 107.1%, with RSD below 8.5% across all studied conditions. Our findings highlight the robustness and applicability of the presented multiplex SERS platform for rapid and accurate detection of bacterial contaminants in complex food systems.</div></div>","PeriodicalId":426,"journal":{"name":"Sensors and Actuators Reports","volume":"11 ","pages":"Article 100433"},"PeriodicalIF":7.6,"publicationDate":"2026-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145921243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-29DOI: 10.1016/j.snr.2025.100431
Ranil C. T․ Temgoua, Jan Lisec, Matthias Koch
Phenylurea herbicides (PUHs) are extensively used in modern agriculture due to their high efficiency in weed control; however, their widespread application has led to persistent environmental contamination and growing public health concerns. Reliable, sensitive, and selective analytical methods are therefore essential for monitoring these compounds in environmental and food matrices. Although several recent reviews have addressed electrochemical sensors and biosensors for a broad range of pollutants, there is currently no dedicated review focusing exclusively on PUHs while integrating electrochemical sensors, biosensors, molecularly imprinted polymers (MIPs), and electrochemical detection coupled with liquid chromatography (LC). This review provides a comprehensive and critical overview of electrochemical strategies developed for the analysis of PUHs. Core electroanalytical techniques, including cyclic voltammetry (CV), differential pulse voltammetry (DPV), square wave voltammetry (SWV), and chronoamperometry (CA), are discussed in terms of their fundamental principles, analytical roles, and suitability for mechanistic investigation, quantitative determination, and rapid screening. Electrochemical impedance spectroscopy (EIS) is also examined, particularly for its application in the characterization of electrode interfaces and in electrochemical biosensor development. Furthermore, the integration of electrochemical methods with mass spectrometry is highlighted as a powerful approach for elucidating redox mechanisms and identifying electrochemical transformation products. More than one hundred electrochemical sensors and biosensors reported between 1993 and 2025 are critically evaluated, with emphasis on electrode materials, surface modification strategies, detection mechanisms, analytical performance, and applicability to real samples. The advantages and limitations of electrochemical sensors, biosensors, and MIP-based platforms are systematically discussed in the context of sensitivity, selectivity, response time, and matrix effects. By synthesizing current advances and identifying remaining challenges, this review aims to provide clear guidance for future research and to support the development of robust, efficient, and application-oriented electrochemical methods for PUHs analysis.
{"title":"Recent advances in electrochemical analysis of phenylurea herbicides","authors":"Ranil C. T․ Temgoua, Jan Lisec, Matthias Koch","doi":"10.1016/j.snr.2025.100431","DOIUrl":"10.1016/j.snr.2025.100431","url":null,"abstract":"<div><div>Phenylurea herbicides (PUHs) are extensively used in modern agriculture due to their high efficiency in weed control; however, their widespread application has led to persistent environmental contamination and growing public health concerns. Reliable, sensitive, and selective analytical methods are therefore essential for monitoring these compounds in environmental and food matrices. Although several recent reviews have addressed electrochemical sensors and biosensors for a broad range of pollutants, there is currently no dedicated review focusing exclusively on PUHs while integrating electrochemical sensors, biosensors, molecularly imprinted polymers (MIPs), and electrochemical detection coupled with liquid chromatography (LC). This review provides a comprehensive and critical overview of electrochemical strategies developed for the analysis of PUHs. Core electroanalytical techniques, including cyclic voltammetry (CV), differential pulse voltammetry (DPV), square wave voltammetry (SWV), and chronoamperometry (CA), are discussed in terms of their fundamental principles, analytical roles, and suitability for mechanistic investigation, quantitative determination, and rapid screening. Electrochemical impedance spectroscopy (EIS) is also examined, particularly for its application in the characterization of electrode interfaces and in electrochemical biosensor development. Furthermore, the integration of electrochemical methods with mass spectrometry is highlighted as a powerful approach for elucidating redox mechanisms and identifying electrochemical transformation products. More than one hundred electrochemical sensors and biosensors reported between 1993 and 2025 are critically evaluated, with emphasis on electrode materials, surface modification strategies, detection mechanisms, analytical performance, and applicability to real samples. The advantages and limitations of electrochemical sensors, biosensors, and MIP-based platforms are systematically discussed in the context of sensitivity, selectivity, response time, and matrix effects. By synthesizing current advances and identifying remaining challenges, this review aims to provide clear guidance for future research and to support the development of robust, efficient, and application-oriented electrochemical methods for PUHs analysis.</div></div>","PeriodicalId":426,"journal":{"name":"Sensors and Actuators Reports","volume":"11 ","pages":"Article 100431"},"PeriodicalIF":7.6,"publicationDate":"2025-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145972831","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-29DOI: 10.1016/j.snr.2025.100432
Haoyue Ma , Ying Liang , Jiangnan Wang , Wanjuan Lin , Yang Pan , Peng Cao , Yue Zhang
The development of colorimetric biosensors offers a promising tool for on-site visual analysis of medicinal plants and related products in market regulation. However, compared to fluorescent or electrochemical sensing strategies, colorimetric sensors often suffer from weak signals and limited sensitivity, making it challenging to detect low-abundance RNA targets in commercial samples. In response to this issue, here we design a triple signal amplification strategy to achieve ultrasensitive colorimetric signal output for visible microRNA (miRNA) detection in medicinal plants and products, and the smartphone-based imaging enabled portable quantitative analysis for on-site market regulation. The specifically expressed miRNA in ginseng is chosen as the target strand to initiate the first amplification (hybridization chain reaction) for DNAzyme activation, catalyzing the successive cleavage of substrate strands for the liberation of trigger strands that drive rolling circle amplification. This process produces a high abundance of repetitive G-quadruplex motifs, which function as catalytic scaffolds to accelerate a colorimetric reaction, ultimately enabling sensitive and reliable detection by the naked eye. Combining three amplification approaches into a unified cascade, this strategy generates distinguishable colorimetric signals with naked eyes, and the quantitative analysis could be achieved using a smartphone software, offering a wide dynamic range (1–105 pM) and a low detection limit of 651 fM. Successful application in medicinal plant ginseng and related products demonstrates the practicality for real sample analysis. The modular amplification design holds broad potential for detecting other molecular targets, underscoring its promise for portable biosensing and on-site regulatory applications.
{"title":"Triple-amplification-assisted visual miRNA sensing for portable identification of medicinal plants and productions","authors":"Haoyue Ma , Ying Liang , Jiangnan Wang , Wanjuan Lin , Yang Pan , Peng Cao , Yue Zhang","doi":"10.1016/j.snr.2025.100432","DOIUrl":"10.1016/j.snr.2025.100432","url":null,"abstract":"<div><div>The development of colorimetric biosensors offers a promising tool for on-site visual analysis of medicinal plants and related products in market regulation. However, compared to fluorescent or electrochemical sensing strategies, colorimetric sensors often suffer from weak signals and limited sensitivity, making it challenging to detect low-abundance RNA targets in commercial samples. In response to this issue, here we design a triple signal amplification strategy to achieve ultrasensitive colorimetric signal output for visible microRNA (miRNA) detection in medicinal plants and products, and the smartphone-based imaging enabled portable quantitative analysis for on-site market regulation. The specifically expressed miRNA in ginseng is chosen as the target strand to initiate the first amplification (hybridization chain reaction) for DNAzyme activation, catalyzing the successive cleavage of substrate strands for the liberation of trigger strands that drive rolling circle amplification. This process produces a high abundance of repetitive G-quadruplex motifs, which function as catalytic scaffolds to accelerate a colorimetric reaction, ultimately enabling sensitive and reliable detection by the naked eye. Combining three amplification approaches into a unified cascade, this strategy generates distinguishable colorimetric signals with naked eyes, and the quantitative analysis could be achieved using a smartphone software, offering a wide dynamic range (1–10<sup>5</sup> pM) and a low detection limit of 651 fM. Successful application in medicinal plant ginseng and related products demonstrates the practicality for real sample analysis. The modular amplification design holds broad potential for detecting other molecular targets, underscoring its promise for portable biosensing and on-site regulatory applications.</div></div>","PeriodicalId":426,"journal":{"name":"Sensors and Actuators Reports","volume":"11 ","pages":"Article 100432"},"PeriodicalIF":7.6,"publicationDate":"2025-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145921241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-26DOI: 10.1016/j.snr.2025.100428
Yong Whan Kim , Seung Yong Lee , Sol Han , Min Young Kim , Jiyeon Shin , Jimyeong Park , Myung Sik choi , Changhyun Jin , Kyu Hyoung Lee , Jeong Yun Hwang
TiO2 generates charge carriers under light irradiation, which are transported to chemical molecules to drive catalytic reactions or serve as signals for detecting hazardous chemicals. Considering the higher light absorption, improved charge-carrier separation, and suppressed recombination, leading to photocurrent generation, black TiO2, with a higher concentration of oxygen vacancies in the rutile phase, has been proposed as a promising candidate. In this work, we applied black TiO2 to chemiresistive gas sensing, achieving not only a higher gas response at room temperature but also exclusively enhanced ethanol sensitivity under UV illumination. Increasing oxygen-vacancy concentration and reduced-valence Ti (e.g., Ti³⁺) progressively convert pristine white TiO2 into yellow and black forms, which correlates with enhanced gas detection. Under UV illumination, the ethanol response of black TiO2 increases by ∼20 % relative to the no-UV condition, consistent with a photocurrent-assisted mechanism. These results demonstrate that higher UV-active black TiO2 suggests that UV-active black TiO2 facilitates ethanol adsorption/detection via weakened Ti–O bonding. Regarding the higher physisorption contribution for room temperature operational gas sensing, modulating surface electron density from OV, reduced Ti cation ratio and photocurrent on chromatic TiO2 is possible to provide platforms for low temperature operable chemical application.
{"title":"Independently enhanced ethanol detection using photocurrent on higher surface electron density of rutile black TiO2","authors":"Yong Whan Kim , Seung Yong Lee , Sol Han , Min Young Kim , Jiyeon Shin , Jimyeong Park , Myung Sik choi , Changhyun Jin , Kyu Hyoung Lee , Jeong Yun Hwang","doi":"10.1016/j.snr.2025.100428","DOIUrl":"10.1016/j.snr.2025.100428","url":null,"abstract":"<div><div>TiO<sub>2</sub> generates charge carriers under light irradiation, which are transported to chemical molecules to drive catalytic reactions or serve as signals for detecting hazardous chemicals. Considering the higher light absorption, improved charge-carrier separation, and suppressed recombination, leading to photocurrent generation, black TiO<sub>2</sub>, with a higher concentration of oxygen vacancies in the rutile phase, has been proposed as a promising candidate. In this work, we applied black TiO<sub>2</sub> to chemiresistive gas sensing, achieving not only a higher gas response at room temperature but also exclusively enhanced ethanol sensitivity under UV illumination. Increasing oxygen-vacancy concentration and reduced-valence Ti (e.g., Ti³⁺) progressively convert pristine white TiO<sub>2</sub> into yellow and black forms, which correlates with enhanced gas detection. Under UV illumination, the ethanol response of black TiO<sub>2</sub> increases by ∼20 % relative to the no-UV condition, consistent with a photocurrent-assisted mechanism. These results demonstrate that higher UV-active black TiO<sub>2</sub> suggests that UV-active black TiO<sub>2</sub> facilitates ethanol adsorption/detection via weakened Ti–O bonding. Regarding the higher physisorption contribution for room temperature operational gas sensing, modulating surface electron density from O<sub>V</sub>, reduced Ti cation ratio and photocurrent on chromatic TiO<sub>2</sub> is possible to provide platforms for low temperature operable chemical application.</div></div>","PeriodicalId":426,"journal":{"name":"Sensors and Actuators Reports","volume":"11 ","pages":"Article 100428"},"PeriodicalIF":7.6,"publicationDate":"2025-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145921240","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-25DOI: 10.1016/j.snr.2025.100429
C.A. Ku, C.Y. Yang, C.Y. Yu, C.K. Chung
Surface-enhanced Raman scattering (SERS) is an effective optical detection method for tracing amounts of toxic substances, with applications in drug detection, environmental and food safety. In the SERS measurements of malachite green (MG) and salicylic acid (SA), metal nanoparticles (MNPs) or core-shell nanostructures are commonly used. However, the preparation of these nanostructures typically requires at least 12 h. Compared to these complex and time-consuming fabrication methods, porous AAO templates offer a facile and stable SERS measurement substrate. We develop a rapid and efficient through-hole AAO fabrication method for SERS detection of MG and SA. The 2D-3D structures at the bottom of these membranes provide more hotspots from sharp tips and concaves, effectively enhancing the SERS signal intensity and improving limits of detection (LOD). For MG detection, the LOD of 10−10 M and analytical enhancement factor (AEF) of 2.67×105 was achieved, with bottom surface of the membrane providing 2–5 times higher signal intensity compared to top surface. Among different AAO nanostructures, AAO prepared at 40 V showed a 1.2–2 times signal enhancement compared to 100/-4 V, attributed to the smaller interpore distance, which effectively enhances the local electrical field on the AAO substrate. The COMSOL simulation of the electric field enhancement by 2D-3D nanostructures is also performed. The calculated relative standard deviations (RSD) within 5 points are 8.23 % and 8.14 %, indicating that the 2D-3D through-hole membrane structure exhibits excellent uniformity. By applying AAO membranes to SA and real sample detection, the LOD of 1 ppm is achieved. This detection method can help in detecting MG and SA in fields like aquaculture, food safety, and daily items.
{"title":"A high-performance 2D-3D SERS substrate with facile through-hole nanoporous anodic alumina membrane for malachite green and salicylic acid detection","authors":"C.A. Ku, C.Y. Yang, C.Y. Yu, C.K. Chung","doi":"10.1016/j.snr.2025.100429","DOIUrl":"10.1016/j.snr.2025.100429","url":null,"abstract":"<div><div>Surface-enhanced Raman scattering (SERS) is an effective optical detection method for tracing amounts of toxic substances, with applications in drug detection, environmental and food safety. In the SERS measurements of malachite green (MG) and salicylic acid (SA), metal nanoparticles (MNPs) or core-shell nanostructures are commonly used. However, the preparation of these nanostructures typically requires at least 12 h. Compared to these complex and time-consuming fabrication methods, porous AAO templates offer a facile and stable SERS measurement substrate. We develop a rapid and efficient through-hole AAO fabrication method for SERS detection of MG and SA. The 2D-3D structures at the bottom of these membranes provide more hotspots from sharp tips and concaves, effectively enhancing the SERS signal intensity and improving limits of detection (LOD). For MG detection, the LOD of 10<sup>−10</sup> M and analytical enhancement factor (AEF) of 2.67×10<sup>5</sup> was achieved, with bottom surface of the membrane providing 2–5 times higher signal intensity compared to top surface. Among different AAO nanostructures, AAO prepared at 40 V showed a 1.2–2 times signal enhancement compared to 100/-4 V, attributed to the smaller interpore distance, which effectively enhances the local electrical field on the AAO substrate. The COMSOL simulation of the electric field enhancement by 2D-3D nanostructures is also performed. The calculated relative standard deviations (RSD) within 5 points are 8.23 % and 8.14 %, indicating that the 2D-3D through-hole membrane structure exhibits excellent uniformity. By applying AAO membranes to SA and real sample detection, the LOD of 1 ppm is achieved. This detection method can help in detecting MG and SA in fields like aquaculture, food safety, and daily items.</div></div>","PeriodicalId":426,"journal":{"name":"Sensors and Actuators Reports","volume":"11 ","pages":"Article 100429"},"PeriodicalIF":7.6,"publicationDate":"2025-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145921165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-25DOI: 10.1016/j.snr.2025.100427
Tingfang Bai , Wenfeng Hai , Ying Ying , Jiaxin Liu , Xinying Guo , Jinghai Liu , Yushuang Liu , Ai Jun
Non-enzymatic glucose detection remains challenging due to poor selectivity and instability in complex biological environments. Here, we developed an organic electrochemical transistor (OECT) incorporating a CH2Cl2-derived poly(EDOT-FPBA) gate to enhance glucose sensing performance.
A solvent-controlled electropolymerization strategy was employed to construct an ordered polymer-brush architecture, enabling efficient ion transport and improved exposure of boronic-acid recognition sites. Structural and electrical characterizations confirmed the brush-like morphology and its strong gate modulation capability. The device exhibited a pronounced gate-voltage shift(ΔVG) of ≈82.0 mV, a broad linear range (0.001–40 mmol⸱L-1), and a low detection limit (5.6 µmol⸱L-1), with interference below 15%, repeatability within a relative standard deviation of 4.6%, and serum recoveries of 92.0–107.4%. This strategy provides a promising route for developing low-voltage, enzyme-free OECT for reliable glucose monitoring in complex biological systems.
{"title":"Surface-engineered polymer brush gate electrodes enable high-sensitivity label-free glucose detection via organic electrochemical transistor","authors":"Tingfang Bai , Wenfeng Hai , Ying Ying , Jiaxin Liu , Xinying Guo , Jinghai Liu , Yushuang Liu , Ai Jun","doi":"10.1016/j.snr.2025.100427","DOIUrl":"10.1016/j.snr.2025.100427","url":null,"abstract":"<div><div>Non-enzymatic glucose detection remains challenging due to poor selectivity and instability in complex biological environments. Here, we developed an organic electrochemical transistor (OECT) incorporating a CH<sub>2</sub>Cl<sub>2</sub>-derived poly(EDOT-FPBA) gate to enhance glucose sensing performance.</div><div>A solvent-controlled electropolymerization strategy was employed to construct an ordered polymer-brush architecture, enabling efficient ion transport and improved exposure of boronic-acid recognition sites. Structural and electrical characterizations confirmed the brush-like morphology and its strong gate modulation capability. The device exhibited a pronounced gate-voltage shift(ΔV<sub>G</sub>) of ≈82.0 mV, a broad linear range (0.001–40 mmol⸱L<sup>-1</sup>), and a low detection limit (5.6 µmol⸱L<sup>-1</sup>), with interference below 15%, repeatability within a relative standard deviation of 4.6%, and serum recoveries of 92.0–107.4%. This strategy provides a promising route for developing low-voltage, enzyme-free OECT for reliable glucose monitoring in complex biological systems.</div></div>","PeriodicalId":426,"journal":{"name":"Sensors and Actuators Reports","volume":"11 ","pages":"Article 100427"},"PeriodicalIF":7.6,"publicationDate":"2025-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145921166","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-25DOI: 10.1016/j.snr.2025.100426
Miguel Tavares , Lucas Lima Bezerra , Cristina Delerue-Matos , Adriana Nunes Correia , Norberto de Kássio Vieira Monteiro , Álvaro Torrinha , Simone Morais
A novel electrochemical sensor of carbon paper (CP) modified with a copper-trimesic acid metal-organic framework (Cu-BTC) was developed for determination of metformin (MET) in complex environmental matrices. MET is one of the most prescribed pharmaceuticals worldwide, posing a potential environmental risk being thus marked by the European Union as a priority contaminant for monitoring. The CP modification was performed through an environmentally friendly layer-by-layer method, and the CP/Cu-BTC sensor was characterized morphologically and structurally. Voltametric analysis revealed a well-defined and irreversible oxidation peak at 0.92 V in contrast with no peak when a bare CP was used, which highlights the importance of Cu-BTC in the detection process. This was confirmed by computational studies that revealed that MET interacts spontaneously with Cu-BTC through hydrogen bonds and van der Waals forces. The electroanalytical conditions (electrolyte pH (8), technique parameters and analyte pre-concentration, +0.4 V and 150 s) were optimized to maximize sensitivity and selectivity. The sensor showed two linear detection ranges (0.11–1.5 and 1.5–10 µM) with high sensitivities (207.6±2.1 and 170.2±4.1 μA µM⁻¹ cm⁻²) and low detection limits (0.037 and 0.52 µM), resulting in a quantification limit (0.11 µM) that is significantly below the established threshold by the European Commission Implementing Decision 2025/439. CP/Cu-BTC exhibited excellent reproducibility, selectivity, and accuracy (80.0–91.3 %) in wastewater, river water and fish samples with minimum extraction steps. Overall, it offers a competitive, cost-effective, and relevant method for monitoring MET in aquatic ecosystems, with potential to compete with the currently applied techniques.
{"title":"Carbon paper/copper metal-organic framework sensor for detection of the European Union watch list substance metformin: electroanalysis and computational mechanistic insights","authors":"Miguel Tavares , Lucas Lima Bezerra , Cristina Delerue-Matos , Adriana Nunes Correia , Norberto de Kássio Vieira Monteiro , Álvaro Torrinha , Simone Morais","doi":"10.1016/j.snr.2025.100426","DOIUrl":"10.1016/j.snr.2025.100426","url":null,"abstract":"<div><div>A novel electrochemical sensor of carbon paper (CP) modified with a copper-trimesic acid metal-organic framework (Cu-BTC) was developed for determination of metformin (MET) in complex environmental matrices. MET is one of the most prescribed pharmaceuticals worldwide, posing a potential environmental risk being thus marked by the European Union as a priority contaminant for monitoring. The CP modification was performed through an environmentally friendly layer-by-layer method, and the CP/Cu-BTC sensor was characterized morphologically and structurally. Voltametric analysis revealed a well-defined and irreversible oxidation peak at 0.92 V in contrast with no peak when a bare CP was used, which highlights the importance of Cu-BTC in the detection process. This was confirmed by computational studies that revealed that MET interacts spontaneously with Cu-BTC through hydrogen bonds and van der Waals forces. The electroanalytical conditions (electrolyte pH (8), technique parameters and analyte pre-concentration, +0.4 V and 150 s) were optimized to maximize sensitivity and selectivity. The sensor showed two linear detection ranges (0.11–1.5 and 1.5–10 µM) with high sensitivities (207.6±2.1 and 170.2±4.1 μA µM⁻¹ cm⁻²) and low detection limits (0.037 and 0.52 µM), resulting in a quantification limit (0.11 µM) that is significantly below the established threshold by the European Commission Implementing Decision 2025/439. CP/Cu-BTC exhibited excellent reproducibility, selectivity, and accuracy (80.0–91.3 %) in wastewater, river water and fish samples with minimum extraction steps. Overall, it offers a competitive, cost-effective, and relevant method for monitoring MET in aquatic ecosystems, with potential to compete with the currently applied techniques.</div></div>","PeriodicalId":426,"journal":{"name":"Sensors and Actuators Reports","volume":"11 ","pages":"Article 100426"},"PeriodicalIF":7.6,"publicationDate":"2025-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145921236","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-25DOI: 10.1016/j.snr.2025.100430
Pedro Dobroes Fonseca , Wilson Antunes , Susana Cardoso
Magnetic nanoparticles are critical components in biosensors for pathogen detection, enabling magnetic capture, signal amplification, and integration with microfluidic systems. However, the nanoscale mechanisms underlying magnetic nanoparticle–bacteria interactions remain poorly characterised, limiting labelling reproducibility and biosensor sensitivity. This study employed super-resolution stochastic optical reconstruction microscopy (STORM) and scanning electron microscopy (SEM) to investigate the spatial distribution of magnetic nanoparticles on 2 µm polystyrene beads and Bacillus cereus spores, used as a safe surrogate for Bacillus anthracis. STORM imaging revealed clustered antibody binding at the spore periphery, consistent with structured epitope presentation in the exosporium. Over 80% of localisations were assigned to nanoclusters, confirming non-random antigen distribution. SEM analysis demonstrated that 100 nm dextran-coated iron oxide magnetic nanoparticles provided superior surface dispersion and lower aggregation compared to 250 nm dextran-coated iron oxide magnetic nanoparticles. A vacuum-assisted filtration protocol significantly enhanced magnetic nanoparticle uniformity and specificity while removing loosely associated aggregates. These findings support the use of 100 nm magnetic nanoparticles for biosensor integration and establish a robust image-based workflow for assessing nanoparticle binding at single-cell resolution. This work provides mechanistic insight into bacterial surface labelling and offers a framework for optimising magnetic labelling strategies for future biosensing and diagnostic applications.
{"title":"Characterisation of bacterial-nanoparticle interactions via STORM and SEM: Optimising magnetic labelling strategies for biosensor integration","authors":"Pedro Dobroes Fonseca , Wilson Antunes , Susana Cardoso","doi":"10.1016/j.snr.2025.100430","DOIUrl":"10.1016/j.snr.2025.100430","url":null,"abstract":"<div><div>Magnetic nanoparticles are critical components in biosensors for pathogen detection, enabling magnetic capture, signal amplification, and integration with microfluidic systems. However, the nanoscale mechanisms underlying magnetic nanoparticle–bacteria interactions remain poorly characterised, limiting labelling reproducibility and biosensor sensitivity. This study employed super-resolution stochastic optical reconstruction microscopy (STORM) and scanning electron microscopy (SEM) to investigate the spatial distribution of magnetic nanoparticles on 2 µm polystyrene beads and <em>Bacillus cereus</em> spores, used as a safe surrogate for <em>Bacillus anthracis</em>. STORM imaging revealed clustered antibody binding at the spore periphery, consistent with structured epitope presentation in the exosporium. Over 80% of localisations were assigned to nanoclusters, confirming non-random antigen distribution. SEM analysis demonstrated that 100 nm dextran-coated iron oxide magnetic nanoparticles provided superior surface dispersion and lower aggregation compared to 250 nm dextran-coated iron oxide magnetic nanoparticles. A vacuum-assisted filtration protocol significantly enhanced magnetic nanoparticle uniformity and specificity while removing loosely associated aggregates. These findings support the use of 100 nm magnetic nanoparticles for biosensor integration and establish a robust image-based workflow for assessing nanoparticle binding at single-cell resolution. This work provides mechanistic insight into bacterial surface labelling and offers a framework for optimising magnetic labelling strategies for future biosensing and diagnostic applications.</div></div>","PeriodicalId":426,"journal":{"name":"Sensors and Actuators Reports","volume":"11 ","pages":"Article 100430"},"PeriodicalIF":7.6,"publicationDate":"2025-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145972833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-24DOI: 10.1016/j.snr.2025.100425
Somayeh Hamd Ghadareh , Kurdistan Fakhraldin Azeez , Abdollah Salimi
Ovarian cancer remains a leading cause of cancer-related mortality due to its asymptomatic progression and late diagnosis. Herein, we present an ultrasensitive ratiometric fluorescence assay for detecting cancer antigen 125 (CA125), a key biomarker of ovarian cancer. This assay integrates a photoluminescent aluminum-based metal-organic framework (Al-MOF), antibody-conjugated gold nanoparticles (AuNPs), and cleavable silica nanocapsules (CSNs). The Al-MOF functions as both a recognition probe and an acidic environment generator, emitting fluorescence at 426 nm, while AuNPs serve as Förster resonance energy transfer (FRET) quenchers. CSNs encapsulate cadmium telluride quantum dots (CdTe QDs; λem = 496 nm) and CA125 antigens within a silica shell crosslinked by pH-sensitive diiminodialkyl silane linkers. Upon antigen binding, the CA125 bridges the Al-MOF and AuNPs, inducing proximity-dependent FRET quenching of Al-MOF fluorescence. Concurrently, the acidic environment cleaves the diimine linkers, releasing the encapsulated QDs and antigens. This dual mechanism generates inversely correlated signals including quenched Al-MOF emission at 426 nm and enhanced QD fluorescence at 496 nm under 370 nm excitation. The assay achieves a detection limit of 37.5 nU/mL for Al-MOF/AuNPs and 0.7 nU/mL for the ratiometric readout (F496/F426), demonstrating an 86-fold sensitivity enhancement over single emission systems. High specificity in human serum samples and strong resistance to interference highlight its potential for early and reliable ovarian cancer diagnostics. The dual‑signal immunoassay was further validated against electrochemiluminescence (ECL), confirming its analytical robustness.
{"title":"Unlocking sensitivity: Innovative ratiometric fluorescence methodology for early detection of CA125 in ovarian cancer using pH-responsive nanocapsules integrated with MOF and gold nanoparticles","authors":"Somayeh Hamd Ghadareh , Kurdistan Fakhraldin Azeez , Abdollah Salimi","doi":"10.1016/j.snr.2025.100425","DOIUrl":"10.1016/j.snr.2025.100425","url":null,"abstract":"<div><div>Ovarian cancer remains a leading cause of cancer-related mortality due to its asymptomatic progression and late diagnosis. Herein, we present an ultrasensitive ratiometric fluorescence assay for detecting cancer antigen 125 (CA125), a key biomarker of ovarian cancer. This assay integrates a photoluminescent aluminum-based metal-organic framework (Al-MOF), antibody-conjugated gold nanoparticles (AuNPs), and cleavable silica nanocapsules (CSNs). The Al-MOF functions as both a recognition probe and an acidic environment generator, emitting fluorescence at 426 nm, while AuNPs serve as Förster resonance energy transfer (FRET) quenchers. CSNs encapsulate cadmium telluride quantum dots (CdTe QDs; λem = 496 nm) and CA125 antigens within a silica shell crosslinked by pH-sensitive diiminodialkyl silane linkers. Upon antigen binding, the CA125 bridges the Al-MOF and AuNPs, inducing proximity-dependent FRET quenching of Al-MOF fluorescence. Concurrently, the acidic environment cleaves the diimine linkers, releasing the encapsulated QDs and antigens. This dual mechanism generates inversely correlated signals including quenched Al-MOF emission at 426 nm and enhanced QD fluorescence at 496 nm under 370 nm excitation. The assay achieves a detection limit of 37.5 nU/mL for Al-MOF/AuNPs and 0.7 nU/mL for the ratiometric readout (F<sub>496</sub>/F<sub>426</sub>), demonstrating an 86-fold sensitivity enhancement over single emission systems. High specificity in human serum samples and strong resistance to interference highlight its potential for early and reliable ovarian cancer diagnostics. The dual‑signal immunoassay was further validated against electrochemiluminescence (ECL), confirming its analytical robustness.</div></div>","PeriodicalId":426,"journal":{"name":"Sensors and Actuators Reports","volume":"11 ","pages":"Article 100425"},"PeriodicalIF":7.6,"publicationDate":"2025-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145921242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-19DOI: 10.1016/j.snr.2025.100421
Mengna Wang , Bai Sun , Guangdong Zhou , Yu Cui , Zelin Cao , Kun Wang , Kaikai Gao , Hui Ma , Xinyu Zhang , Xiaoliang Chen , Wenting Yang , Guoqing Tong
It is well known that the assisted reproduction has become the only means for couples with reproductive defects to have a child. However, the optimal embryo transfer in existing assisted reproductive technologies mainly relies on morphological evaluation, and there is currently a lack of precise detection techniques for selecting grade embryos. To address this blank, an innovative embryo detection method based on a memristor with memristive-sensing effect was firstly developed by analyzing the culture medium from different grade embryos, achieving the quantitative and real-time monitoring based on the metabolic and ROS activity. Specifically, it is found that the device can operate through the redistribution of interfacial surface charges induced by OH–/H+ ions adsorption, exhibiting a distance resistance state transition (SET voltage: -1.7 V to +1.4 V at room temperature). Exceptionally low signal fluctuation was also demonstrated by the device in embryo culture medium testing, where the coefficient of variation remained below 20%. Therefore, by integrating innovative memristive-sensing technology, it is aimed to establish an objective, data-driven alternative to conventional morphological assessment, thereby significantly improving the embryos selection accuracy and clinical pregnancy rate.
{"title":"A memristor-based intelligent system for embryonic metabolic monitoring and diagnostic assessment","authors":"Mengna Wang , Bai Sun , Guangdong Zhou , Yu Cui , Zelin Cao , Kun Wang , Kaikai Gao , Hui Ma , Xinyu Zhang , Xiaoliang Chen , Wenting Yang , Guoqing Tong","doi":"10.1016/j.snr.2025.100421","DOIUrl":"10.1016/j.snr.2025.100421","url":null,"abstract":"<div><div>It is well known that the assisted reproduction has become the only means for couples with reproductive defects to have a child. However, the optimal embryo transfer in existing assisted reproductive technologies mainly relies on morphological evaluation, and there is currently a lack of precise detection techniques for selecting grade embryos. To address this blank, an innovative embryo detection method based on a memristor with memristive-sensing effect was firstly developed by analyzing the culture medium from different grade embryos, achieving the quantitative and real-time monitoring based on the metabolic and ROS activity. Specifically, it is found that the device can operate through the redistribution of interfacial surface charges induced by OH<sup>–</sup>/H<sup>+</sup> ions adsorption, exhibiting a distance resistance state transition (SET voltage: -1.7 V to +1.4 V at room temperature). Exceptionally low signal fluctuation was also demonstrated by the device in embryo culture medium testing, where the coefficient of variation remained below 20%. Therefore, by integrating innovative memristive-sensing technology, it is aimed to establish an objective, data-driven alternative to conventional morphological assessment, thereby significantly improving the embryos selection accuracy and clinical pregnancy rate.</div></div>","PeriodicalId":426,"journal":{"name":"Sensors and Actuators Reports","volume":"11 ","pages":"Article 100421"},"PeriodicalIF":7.6,"publicationDate":"2025-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145921247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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