Chemosensors

12 pages, 2870 KB

Open AccessCommunication

A Novel Pyrene-Based Fluorescent Probe for the Detection of Cu²⁺

by Haixia Wang, Ning Xiao, Chen Zhou, Evgeny Kovtunets, Mingxin Luo, Chenyang Zou, Yining Wang and Jing Sun

Chemosensors 2025, 13(11), 403; https://doi.org/10.3390/chemosensors13110403 - 20 Nov 2025

Viewed by 721

Abstract

A novel fluorescent probe (PYB) for selective and sensitive detection of Cu²⁺ ions was rationally designed and synthesized via a multi-step organic reaction using pyrene as the fluorophore and salicylaldehyde-diethylenetriamine Schiff base as the recognition moiety. The structural characterization of PYB was [...] Read more.

A novel fluorescent probe (PYB) for selective and sensitive detection of Cu²⁺ ions was rationally designed and synthesized via a multi-step organic reaction using pyrene as the fluorophore and salicylaldehyde-diethylenetriamine Schiff base as the recognition moiety. The structural characterization of PYB was confirmed by ¹H NMR, ¹³C NMR, and high-resolution mass spectrometry (HRMS). Photophysical properties investigation revealed that the probe exhibited strong fluorescence emission at 362 nm in DMF/HEPES-NaOH buffer solution (v:v = 1:1, pH 7.4), which underwent a significant fluorescence quenching response (quenching efficiency up to 77%) upon the addition of Cu²⁺, attributed to the formation of a 1:1 PYB-Cu²⁺ complex (binding constant K = 799.65 M⁻¹). The probe showed excellent selectivity for Cu²⁺ over other common metal ions (Ba²⁺, Na⁺, Mg²⁺, Zn²⁺, Cd²⁺, Ca²⁺, Mn²⁺, Pb²⁺, Hg²⁺, Fe³⁺, Co²⁺), with a low detection limit of 8.35 × 10⁻⁷ M, which is well below the maximum allowable concentration of Cu²⁺ in drinking water specified by the World Health Organization (WHO). Furthermore, a portable fluorescent test strip based on PYB was successfully fabricated, enabling rapid and visual detection of Cu²⁺ under UV light. Fluorescence imaging experiments in living HepG2 cells demonstrated that PYB could penetrate cell membranes efficiently and realize the intracellular detection of exogenous Cu²⁺. These results collectively indicate that PYB holds great potential as a practical tool for Cu²⁺ detection in environmental monitoring, food safety, and biological systems. Full article

(This article belongs to the Special Issue Advanced Material-Based Fluorescent Sensors)

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33 pages, 5843 KB

Open AccessReview

Exploring Lactate Electrochemical Biosensors: From Current Technologies to Future Market Impact

by Karla Castro, Rafael Matias, Arielly Cardoso, Rafaela C. Freitas, Aline Martins de Oliveira, Tiago Almeida Silva and Bruno C. Janegitz

Chemosensors 2025, 13(11), 402; https://doi.org/10.3390/chemosensors13110402 - 19 Nov 2025

Viewed by 2214

Abstract

Lactic acid is a vital molecule for health and food quality control. Its detection, typically via L-lactate, is a valuable indicator for conditions like disease, product spoilage, and stress. Electrochemical biosensors offer a promising, user-friendly solution for lactate detection. These versatile devices allow [...] Read more.

Lactic acid is a vital molecule for health and food quality control. Its detection, typically via L-lactate, is a valuable indicator for conditions like disease, product spoilage, and stress. Electrochemical biosensors offer a promising, user-friendly solution for lactate detection. These versatile devices allow for tailored surfaces, adapting to sample characteristics, detection mechanisms, and end-user needs. Despite the variety of existing electrochemical biosensor architectures, including microfluidic, wearable, paper-based, carbon-based, and glassy carbon electrode types, routine lactate analysis with these devices remains a significant challenge. This work will explore diverse electrochemical lactate biosensors, detailing their designs, modifications, common transducers, analyzed samples, and validation. We will also survey commercially available options. Finally, this review assesses the current commercialization status and future perspectives of these biosensors, highlighting their growing importance in clinical and industrial applications. Full article

(This article belongs to the Special Issue Nanomaterial-Based Sensors: Design, Development and Applications)

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20 pages, 3477 KB

Open AccessArticle

Computational and Theoretical Methods for Mass-Transport Analysis in 3D-Printed Milli Fluidic Electrochemical Devices with Channel Band Electrodes

by Jesús E. Contreras-Naranjo, Victor H. Perez-Gonzalez, Marco A. Mata-Gómez and Oscar Aguilar

Chemosensors 2025, 13(11), 401; https://doi.org/10.3390/chemosensors13110401 - 19 Nov 2025

Viewed by 849

Abstract

Available models for mass transport in microfluidic electrochemical sensors fall short in capturing critical features of millimeter-scale devices 3D-printed using fused deposition modeling, including inherent porosity and non-flat electrode geometries, thereby reducing their predictive power and transferability. Meanwhile, growing interest in low-cost and [...] Read more.

Available models for mass transport in microfluidic electrochemical sensors fall short in capturing critical features of millimeter-scale devices 3D-printed using fused deposition modeling, including inherent porosity and non-flat electrode geometries, thereby reducing their predictive power and transferability. Meanwhile, growing interest in low-cost and accessible fabrication methodologies has driven the quantitative use of these devices without first understanding the effects of such structural features on current responses. Here, the quantitative electrochemical performance of millimeter-scale 3D-printed devices with channel band electrodes is studied through computational and theoretical methods aimed at understanding their fundamental behavior. Simulations and dimensionless analysis reveal the influence of electrode shape and porosity on current responses under laminar flow. An adjusted Levich model is proposed to incorporate non-flat electrode geometries, while two new analytical models—general and transition-specific—predict currents through all mass transport regimes (convection, diffusion, and transition) that can simultaneously emerge due to porosity effects. Moreover, we introduce a low-cost “print–pause–print” fabrication strategy for such systems, employing a desktop 3D printer and 3D pen, which allows electrode integration and activation through polishing and “in-channel” electrochemical treatment. These advances facilitate developing next-generation 3D-printed milli fluidic electrochemical platforms with improved performance and scalability. Full article

(This article belongs to the Special Issue Electrochemical Sensors and Biosensors: Recent Advances and Future Challenges)

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19 pages, 4869 KB

Open AccessArticle

Geographical Origin Identification of Rhizoma Atractylodis macrocephalae Using Hyperspectral Imaging Combined with Broad Learning System and SHapley Additive exPlanations

by Peng Li, Huaming Liu, Defang Liu, Liguo Han and Chuanzong Li

Chemosensors 2025, 13(11), 400; https://doi.org/10.3390/chemosensors13110400 - 19 Nov 2025

Viewed by 642

Abstract

Rhizoma Atractylodis macrocephalae (RAM) is a renowned food–medicine homologous herb in China, the quality and efficacy of which are inherently linked to its geographical origin. However, traditional origin identification methods for RAM are time-consuming, laborious, and destructive. This study introduces an innovative framework [...] Read more.

Rhizoma Atractylodis macrocephalae (RAM) is a renowned food–medicine homologous herb in China, the quality and efficacy of which are inherently linked to its geographical origin. However, traditional origin identification methods for RAM are time-consuming, laborious, and destructive. This study introduces an innovative framework integrating hyperspectral imaging (HSI), broad learning system (BLS), and SHapley Additive exPlanations (SHAP) for RAM origin identification. RAM samples were collected from three origins, 100 samples from per origin, and imaged using a visible and short-wave near-infrared HSI system. BLS was used to build identification models with full and important wavelengths, and compared against seven traditional algorithms, including K-nearest neighbors (KNN), random forest (RF), support vector machine (SVM), back propagation neural network (BPNN), gradient boosting decision tree, (GBDT), extreme gradient boosting (XGBoost), and adaptive boosting (AdaBoost). Additionally, SHAP was used to enhance interpretability and identify important wavelengths highly correlated with RAM origin. Results showed that the full-wavelength BLS model achieved a test accuracy of 95.56%, which outperformed other models including KNN (77.78%), RF (85.56%), GBDT (88.89%), AdaBoost (90.00%), BPNN (91.11%), XGBoost (92.22%), and SVM (94.44%). SHAP identified important wavelengths similar to traditional methods (competitive adaptive reweighted sampling and successive projections algorithm), and the BLS model using SHAP-selected top 25 wavelengths achieved 94.44% accuracy with minimal performance loss. This study not only provides a rapid and accurate approach for RAM origin identification but also establishes a promising data-driven paradigm for non-destructive geographical origin traceability of other traditional Chinese medicines. Full article

(This article belongs to the Special Issue Technological and Analytical Advances in Hyperspectral Analysis)

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32 pages, 3930 KB

Open AccessReview

Recent Advances in Agricultural Sensors: Towards Precision and Sustainable Farming

by Jiaqi Lin and Shuping Wu

Chemosensors 2025, 13(11), 399; https://doi.org/10.3390/chemosensors13110399 - 14 Nov 2025

Viewed by 2049

Abstract

Global population growth, intensifying climate change, and escalating food security demands are mounting. In response, modern agriculture must transcend the limitations of traditional experience-based cultivation models to address issues such as low resource utilization, poor environmental adaptability, and significant yield fluctuations. As the [...] Read more.

Global population growth, intensifying climate change, and escalating food security demands are mounting. In response, modern agriculture must transcend the limitations of traditional experience-based cultivation models to address issues such as low resource utilization, poor environmental adaptability, and significant yield fluctuations. As the core technical support of smart agriculture, agricultural sensors have become the key to transformation. This review systematically introduces the classification and working principles of current mainstream agricultural sensors: according to the monitoring parameters, they can be divided into humidity sensors, light sensors, gas sensors, pressure sensors, nutrient sensors, etc. At the same time, breakthroughs in emerging technologies such as microneedle sensing, nanosensing, and wireless sensor networks are being explored, which are breaking the application limitations of traditional sensors in complex agricultural environments. Combined with specific cases, the practical value of sensor technology is improving in agricultural drought monitoring, soil detection, and agricultural product quality assessment. Looking ahead, if agricultural sensors can overcome existing limitations through breakthroughs in material innovation, multi-sensor unit integration, and artificial intelligence algorithm fusion, this will provide stronger technological support for the further advancement of smart agriculture. Full article

(This article belongs to the Special Issue Application of Chemical Sensors in Smart Agriculture)

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68 pages, 4761 KB

Open AccessReview

Advances in Molecularly Imprinted Electrochemical Platforms for Food Quality Control: Targeting Antioxidants, Sweeteners, Colorants, Contaminants and Toxicants

by Lu Zhang, Shichao Zhao, Jiangwei Zhu and Li Fu

Chemosensors 2025, 13(11), 398; https://doi.org/10.3390/chemosensors13110398 - 13 Nov 2025

Cited by 2 | Viewed by 2141

Abstract

Ensuring food safety and quality has become increasingly critical due to the complexities introduced by globalization, industrialization, and extended supply chains. Traditional analytical methods for food quality control, such as chromatography and mass spectrometry, while accurate, face limitations including high costs, lengthy analysis [...] Read more.

Ensuring food safety and quality has become increasingly critical due to the complexities introduced by globalization, industrialization, and extended supply chains. Traditional analytical methods for food quality control, such as chromatography and mass spectrometry, while accurate, face limitations including high costs, lengthy analysis times, and limited suitability for on-site rapid monitoring. Electrochemical sensors integrated with molecularly imprinted polymers (MIPs) have emerged as promising alternatives, combining high selectivity and sensitivity with portability and affordability. MIPs, often termed ‘plastic antibodies,’ are synthetic receptors capable of selective molecular recognition, tailored specifically for target analytes. This review comprehensively discusses recent advancements in MIP-based electrochemical sensing platforms, highlighting their applications in detecting various food quality markers. It particularly emphasizes the detection of antioxidants—both natural (e.g., vitamins, phenolics) and synthetic (e.g., BHA, TBHQ), artificial sweeteners (e.g., aspartame, acesulfame-K), colorants (e.g., azo dyes, anthocyanins), traditional contaminants (e.g., pesticides, heavy metals), and toxicants such as mycotoxins (e.g., aflatoxins, ochratoxins). The synthesis methods, including bulk, precipitation, surface imprinting, sol–gel polymerization, and electropolymerization (EP), are critically evaluated for their effectiveness in creating highly selective binding sites. Furthermore, the integration of advanced nanomaterials, such as graphene, carbon nanotubes, and metallic nanoparticles, into these platforms to enhance sensitivity, selectivity, and stability is examined. Practical challenges, including sensor reusability, regeneration strategies, and adaptability to complex food matrices, are addressed. Finally, the review provides an outlook on future developments and practical considerations necessary to transition these innovative MIP electrochemical sensors from laboratory research to widespread adoption in industry and regulatory settings, ultimately ensuring comprehensive food safety and consumer protection. Full article

(This article belongs to the Special Issue Molecularly Imprinted Polymer (MIP) Sensors)

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22 pages, 7271 KB

Open AccessArticle

Hierarchical Super-Hydrophilic Aluminum Oxide Architectures on Textured Silicon for Aqueous- and Vapor-Phase Interaction

by Hyo-Ryoung Lim, Tae Woong Yun, Nu Si A Eom, Doyoun Kim, Chae Yeon Hong and Yong-Ho Choa

Chemosensors 2025, 13(11), 397; https://doi.org/10.3390/chemosensors13110397 - 13 Nov 2025

Viewed by 828

Abstract

Hierarchical super-hydrophilic surfaces were realized by forming porous anodic aluminum oxide (AAO) and boehmite [AlO(OH)] on micro-textured Si wafers. One-step anodization of e-beam-deposited Al followed by controlled pore-widening, thermal annealing, or hot-water treatment produced oxide architectures exhibiting near-zero water contact angles (aqueous regime) [...] Read more.

Hierarchical super-hydrophilic surfaces were realized by forming porous anodic aluminum oxide (AAO) and boehmite [AlO(OH)] on micro-textured Si wafers. One-step anodization of e-beam-deposited Al followed by controlled pore-widening, thermal annealing, or hot-water treatment produced oxide architectures exhibiting near-zero water contact angles (aqueous regime) and pronounced H₂O adsorption–desorption responses (vapor regime). Thermogravimetric analysis, moisture isotherms, and FT-IR indicate that increased porosity and anion incorporation (O⁻/O²⁻/oxalate) enrich surface hydroxyl functionality, enhancing affinity to H₂O. The results delineate two complementary regimes—rapid capillary wetting and multilayer vapor adsorption—supporting the use of these oxide/Si hierarchies as interactive water-affine interfaces with potential relevance to moisture gettering and chemosensing. Full article

(This article belongs to the Special Issue Functionalized Material-Based Gas Sensing)

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17 pages, 3921 KB

Open AccessArticle

A Label-Free Fluorescence Polarization for Protein Detection Based on Albumin Nanoparticles

by Yunshu Wang, Ruixin An, Fengwei Liu, Zeyan Dong, Sheng Yang and Siyu Liu

Chemosensors 2025, 13(11), 396; https://doi.org/10.3390/chemosensors13110396 - 12 Nov 2025

Viewed by 629

Abstract

Human serum albumin (HSA), an endogenous protein, was employed in the synthesis of nanoparticles. The treatment of an HSA solution with ethanol and glutaraldehyde resulted in the formation of human serum albumin nanoparticles (HSA NPs), which exhibited a weak fluorescence emission peak at [...] Read more.

Human serum albumin (HSA), an endogenous protein, was employed in the synthesis of nanoparticles. The treatment of an HSA solution with ethanol and glutaraldehyde resulted in the formation of human serum albumin nanoparticles (HSA NPs), which exhibited a weak fluorescence emission peak at 515 nm upon excitation at 360 nm. Importantly, these synthesized HSA NPs displayed a pronounced fluorescence polarization (FP) signal under identical excitation and emission conditions. Furthermore, incubation of the HSA NPs with specific DNA aptamers targeting lysozyme and thrombin led to a significant decrease in the FP values. This reduction in FP was effectively reversed upon the addition of lysozyme and thrombin. Based on these observations, a label-free fluorescence polarization-based detection platform for lysozyme and thrombin was developed utilizing HSA NPs and a DNA aptamer system. Full article

(This article belongs to the Special Issue Advanced Colorimetric and Fluorescent Sensors and Their Application in Detection, 2nd Edition)

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24 pages, 2813 KB

Open AccessArticle

Development of a Calibration Transfer Methodology and Experimental Setup for Urine Headspace Analysis

by Michela Cassinerio, Beatrice Julia Lotesoriere, Stefano Robbiani, Emanuele Zanni, Fabio Grizzi, Gianluigi Taverna, Raffaele Dellacà and Laura Maria Teresa Capelli

Chemosensors 2025, 13(11), 395; https://doi.org/10.3390/chemosensors13110395 - 12 Nov 2025

Viewed by 743

Abstract

Electronic noses (E-Noses) equipped with metal-oxide semiconductor (MOS) sensors are promising tools for non-invasive medical diagnostics. Their adoption in clinical practice, however, is limited—among others—by sensor variability across devices, which makes individual calibration necessary. This study presents an approach for the development of [...] Read more.

Electronic noses (E-Noses) equipped with metal-oxide semiconductor (MOS) sensors are promising tools for non-invasive medical diagnostics. Their adoption in clinical practice, however, is limited—among others—by sensor variability across devices, which makes individual calibration necessary. This study presents an approach for the development of a calibration transfer (CT) methodology for urine headspace analysis, involving the design and realization of a dedicated experimental setup and protocol. Partial least squares-discriminant analysis (PLS-DA) models were trained on human urine samples enriched with selected biomarkers to simulate pathological states. Models from a reference (“master”) device were transferred to other (“slave”) units in multiple master–slave configurations using Direct Standardization (DS). To overcome the variability of human urine, synthetic urine recipes were formulated to mimic sensor responses and serve as reproducible transfer samples. Several strategies for selecting transfer samples were evaluated, including the Kennard–Stone algorithm, a DBSCAN-based approach, and random selection. Without CT, classification accuracy on slave devices decreased markedly (37–55%) compared to the master’s performance (79%), whereas applying DS with synthetic standards restored accuracy to 75–80%. These results demonstrate that combining reproducible synthetic standards with DS enables effective model transfer across E-Noses, reducing calibration requirements and supporting their broader applicability in medical diagnostics. Full article

(This article belongs to the Special Issue Arrays of Bio/Chemical Sensors: Uses and Strategies for Their Application)

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19 pages, 2228 KB

Open AccessArticle

Highly Sensitive Detection Method of Gas Based on the Fabry–Pérot Cavity Using Terahertz Frequency-Domain Spectroscopy

by Yubo Wu, Kanglong Chen, Ayesha Kosar Fahad, Lulu Han and Cunjun Ruan

Chemosensors 2025, 13(11), 394; https://doi.org/10.3390/chemosensors13110394 - 12 Nov 2025

Viewed by 715

Abstract

This study introduces a simple, sensitive, efficient, and low-cost gas detection method in the terahertz range. A mode-adjustable Fabry–Pérot cavity is proposed to enhance detection by tuning the cavity length to match the cavity’s resonant frequency with the gas absorption peak. Terahertz frequency [...] Read more.

This study introduces a simple, sensitive, efficient, and low-cost gas detection method in the terahertz range. A mode-adjustable Fabry–Pérot cavity is proposed to enhance detection by tuning the cavity length to match the cavity’s resonant frequency with the gas absorption peak. Terahertz frequency domain spectroscopy (THz-FDS), offering MHz-level resolution, provides stronger applicability than other spectral systems. Carbon monoxide (CO) is used as the test gas, with its 465 GHz absorption peak validating the coupling enhancement. The experiment measures CO absorption spectra from 0.02 to 1.5 THz, achieving a detection limit of 7%. Using a vacuum cavity to eliminate water vapor interference, low concentrations are detected, with a mode number of m = 10 yielding a detection limit of 3500 ppm, 20 times better than previous results. The impact of different modes on coupling was analyzed, showing more effective coupling when the Q-value of the resonant peak closely matches that of the gas absorption peak. This method demonstrates high sensitivity and applicability for detecting low concentrations of toxic and harmful gases. Full article

(This article belongs to the Section Optical Chemical Sensors)

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34 pages, 8162 KB

Open AccessReview

A Comprehensive Review of Non-Destructive Monitoring of Food Freshness and Safety Using NIR Spectroscopy and Biosensors: Challenges and Opportunities

by Nama Yaa Akyea Prempeh, Xorlali Nunekpeku, Felix Y. H. Kutsanedzie, Arul Murugesan and Huanhuan Li

Chemosensors 2025, 13(11), 393; https://doi.org/10.3390/chemosensors13110393 - 10 Nov 2025

Cited by 2 | Viewed by 2440

Abstract

The demand for safe, high-quality, and minimally processed food has intensified interest in non-destructive analytical techniques capable of assessing freshness and safety in real time. Among these, near-infrared (NIR) spectroscopy and biosensors have emerged as leading technologies due to their rapid, reagent-free, and [...] Read more.

The demand for safe, high-quality, and minimally processed food has intensified interest in non-destructive analytical techniques capable of assessing freshness and safety in real time. Among these, near-infrared (NIR) spectroscopy and biosensors have emerged as leading technologies due to their rapid, reagent-free, and sample-preserving nature. NIR spectroscopy offers a holistic assessment of internal compositional changes, while biosensors provide specific and sensitive detection of biological and chemical contaminants. Recent advances in miniaturization, chemometrics, and deep learning have further enhanced their potential for inline and point-of-need applications across diverse food matrices, including meat, seafood, eggs, fruits, and vegetables. This review critically evaluates the operational principles, instrumentation, and current applications of NIR spectroscopy and biosensors in food freshness and safety monitoring. It also explores their integration, highlights practical challenges such as calibration transfer and regulatory hurdles, and outlines emerging innovations including hybrid sensing, Artificial Intelligence (AI) integration, and smart packaging. The scope of this review is to provide a comprehensive understanding of these technologies, and its objective is to inform future research and industrial deployment strategies that support sustainable, real-time food quality control. These techniques enable near real-time monitoring under laboratory and pilot-scale conditions, showing strong potential for industrial adaptation. The nature of these targets often determines the choice of transduction method. Full article

(This article belongs to the Special Issue Chemometrics Tools Used in Chemical Detection and Analysis)

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12 pages, 1632 KB

Open AccessArticle

Polyethyleneimine-MOF-235 Composite-Enhanced Electrochemical Detection of Silver Nanoparticles in Cosmetics

by Shuo Duan and Huang Dai

Chemosensors 2025, 13(11), 392; https://doi.org/10.3390/chemosensors13110392 - 8 Nov 2025

Cited by 1 | Viewed by 602

Abstract

Silver nanoparticles (AgNPs) are extensively utilized in cosmetics and healthcare products, creating an urgent need for sensitive quantification methods. We report the first application of a metal–organic framework for electrochemical AgNPs sensing in cosmetic samples. A glassy carbon electrode was modified with polyethyleneimine-encapsulated [...] Read more.

Silver nanoparticles (AgNPs) are extensively utilized in cosmetics and healthcare products, creating an urgent need for sensitive quantification methods. We report the first application of a metal–organic framework for electrochemical AgNPs sensing in cosmetic samples. A glassy carbon electrode was modified with polyethyleneimine-encapsulated MOF-235 (PEI-MOF-235/GCE); the PEI layer enriches AgNPs through Ag–N coordination, whereas the high-surface-area MOF catalyzes their oxidative dissolution. Under optimized conditions (catalyst loading 1.4 µg mm⁻³, pH 4.3 PBS), differential-pulse voltammetry provided a linear range of 10–100 ng L⁻¹ and a detection limit of 3.93 ng L⁻¹ (S/N = 3). The sensor exhibited excellent stability (RSD ≤ 4.7%) and good anti-interference capability toward common aquatic ions. Compared with a standard HPLC method, recoveries in spiked cosmetic samples were 97.9–102.6%. This MOF-based strategy offers a sensitive, selective, and field-deployable platform for routine monitoring of trace AgNPs. Full article

(This article belongs to the Special Issue Advancements of Chemosensors and Biosensors in China—3rd Edition)

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17 pages, 1079 KB

Open AccessArticle

Early Detection of Monilinia laxa in Nectarine (Prunus persica var. nectarina) Using Electronic Nose Technology: A Non-Destructive Diagnostic Approach

by Ana Martínez, Alejandro Hernández, Patricia Arroyo, Jesús Lozano, Alberto Martín and María de Guía Córdoba

Chemosensors 2025, 13(11), 391; https://doi.org/10.3390/chemosensors13110391 - 7 Nov 2025

Viewed by 659

Abstract

This study evaluates the application of an electronic nose (E-nose) system as a non-destructive tool for the early detection of Monilinia laxa infection in yellow nectarines (Prunus persica var. nectarine, cv. “Kinolea”) through the analysis of volatile organic compounds (VOCs). Two experimental [...] Read more.

This study evaluates the application of an electronic nose (E-nose) system as a non-destructive tool for the early detection of Monilinia laxa infection in yellow nectarines (Prunus persica var. nectarine, cv. “Kinolea”) through the analysis of volatile organic compounds (VOCs). Two experimental groups were established: a control group of healthy fruit and a treatment group inoculated with the pathogen. The VOCs emitted by both groups were identified and quantified using gas chromatography-mass spectrometry (GC-MS). Simultaneously, the responses of the E-nose were recorded at three critical stages of fungal development: early, intermediate, and advanced. The electronic nose used consists of a set of 11 commercial metal oxide semiconductor (MOX) sensors. The signals from these sensors showed a strong correlation with the VOC profiles associated with fungal deterioration. Linear discriminant analysis (LDA) models based on E-nose data successfully distinguished between healthy and infected samples with 97% accuracy. Furthermore, the system accurately classified samples into three stages of contamination—control, early infection, and advanced infection—with 96% classification accuracy. These findings demonstrate that E-nose technology is an effective, rapid, and non-invasive method for the real-time monitoring of post-harvest fungal contamination in nectarines, offering significant potential for improving quality control during storage and distribution. Full article

(This article belongs to the Special Issue Arrays of Bio/Chemical Sensors: Uses and Strategies for Their Application)

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20 pages, 3654 KB

Open AccessArticle

NO₂ Detection Using Hierarchical WO₃ Microflower-Based Gas Sensors: Comprehensive Study of Sensor Performance

by Paulo V. Morais, Pedro H. Suman and Marcelo O. Orlandi

Chemosensors 2025, 13(11), 390; https://doi.org/10.3390/chemosensors13110390 - 6 Nov 2025

Viewed by 706

Abstract

Monitoring nitrogen dioxide (NO₂) in various scenarios is crucial due to its significant environmental impact as a hazardous gas which is emitted by several industrial sectors. This study reports the optimized synthesis of WO₃ flower-like structures using the microwave-assisted hydrothermal [...] Read more.

Monitoring nitrogen dioxide (NO₂) in various scenarios is crucial due to its significant environmental impact as a hazardous gas which is emitted by several industrial sectors. This study reports the optimized synthesis of WO₃ flower-like structures using the microwave-assisted hydrothermal method under various experimental conditions, resulting in the optimized sample designated MF-WO₃-K2. Structural, morphological, and chemical characterizations revealed that WO₃ microflowers (MF-WO₃-K2) exhibit a hexagonal crystalline phase, a bandgap of 2.4 eV, and a high specific surface area of 61 m²/g. The gas-sensing performance of WO₃ microflowers was investigated by electrical measurements of six similarly fabricated MF-WO₃-K2 sensors. The MF-WO₃-K2 sensors demonstrated a remarkable sensor signal of 225 for 5 ppm NO₂ at 150 °C and response/recovery times of 14.5/2.4 min, coupled with outstanding selectivity against potential interfering gases such as CO, H₂, C₂H₂, and C₂H₄. Additionally, the sensors achieved a low detection limit of 65 ppb for NO₂ at 150 °C. The exceptional sensing properties of WO₃ microflowers are attributed to the abundance of active sites on the surface, large specific surface area, and the presence of pores in the material that facilitate the diffusion of NO₂ molecules into the structure. Overall, the WO₃ microflowers demonstrate a promising ability to be used as a sensitive layer in high-performance chemiresistive gas sensors due to their high sensor performance and good reproducibility for NO₂ detection. Full article

(This article belongs to the Special Issue Functional Nanomaterial-Based Gas Sensors)

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23 pages, 5499 KB

Open AccessArticle

Enhanced Room Temperature NO₂ Detection by Carbon Nanofibers and Single-Walled Carbon Nanotubes: Experimental and Molecular Dynamics

by Arina D. Lozben’, Arina R. Smagulova, Mohammad Khajavian, Valery Golovakhin, Artyom A. Shishin, Sofia A. Shpakova, Dmitriy I. Ostertak, Arina V. Ukhina, Eugene A. Maksimovskiy, Alexandra I. Bogomolova, Dmitry V. Smovzh and Alexander G. Bannov

Chemosensors 2025, 13(11), 389; https://doi.org/10.3390/chemosensors13110389 - 4 Nov 2025

Cited by 1 | Viewed by 934

Abstract

This study explores the development of new room-temperature NO₂ sensors utilizing carbon nanofibers (CNFs), single-walled carbon nanotubes (SWCNTs), and their hybrids with reduced graphite oxide (rGO), fabricated via a facile drop casting method with varying concentrations of carbon/ethanol mixtures. The concentration-dependent relation [...] Read more.

This study explores the development of new room-temperature NO₂ sensors utilizing carbon nanofibers (CNFs), single-walled carbon nanotubes (SWCNTs), and their hybrids with reduced graphite oxide (rGO), fabricated via a facile drop casting method with varying concentrations of carbon/ethanol mixtures. The concentration-dependent relation of sensor response to NO₂ has been found. Comprehensive characterization techniques, including electron microscopy, Raman spectroscopy, optical microscopy, and X-ray diffraction were employed to analyze the sensing materials. Our results reveal that CNFs exhibit superior sensitivity, reaching −1.32%/ppm at an optimal suspension concentration of 1.5 mg/mL, outperforming SWCNTs. The creation of hybrid composites, specifically CNFs/rGO and SWCNTs/rGO, further enhances sensing performance due to synergistic effects. Molecular dynamics simulations revealed increased adsorption behavior of the CNFs/rGO hybrid sensing material. The fabricated devices, based on all-carbon composites, are effective and energy-efficient platforms for NO₂ detection, offering promising solutions for environmental monitoring, the chemical industry, and industrial safety applications. Full article

(This article belongs to the Section Applied Chemical Sensors)

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22 pages, 3823 KB

Open AccessReview

Carbon Nanotube-Based Self-Powered Sensors for Autonomous Environmental and Biomedical Monitoring

by Minwoo Kim, Younghun Noh, Hyunsoo Kim and Yongwoo Jang

Chemosensors 2025, 13(11), 388; https://doi.org/10.3390/chemosensors13110388 - 4 Nov 2025

Cited by 1 | Viewed by 1603

Abstract

Self-powered sensor technologies are receiving increasing attention owing to their ability to operate independently without the need for external batteries or power supplies. This autonomy enables continuous and real-time monitoring in various applications. Carbon nanotubes (CNTs) are particularly promising as electrode materials and [...] Read more.

Self-powered sensor technologies are receiving increasing attention owing to their ability to operate independently without the need for external batteries or power supplies. This autonomy enables continuous and real-time monitoring in various applications. Carbon nanotubes (CNTs) are particularly promising as electrode materials and energy-harvesting components, owing to their excellent electrical conductivity, mechanical robustness, and tunable surface properties. This review provides a concise overview and critical perspectives on recent progress in CNT-based self-powered sensors, focusing on their structural designs, operating mechanisms, and application areas. The sensors are classified according to their practical application environments, including environmental, wearable, and implantable applications, rather than by their energy-harvesting mechanisms or detection targets. Furthermore, current critical challenges, such as durability, scalable fabrication, and in vivo validation, which must be solved to achieve fully autonomous CNT-based sensors for healthcare and environmental monitoring, are discussed. This review underscores the pivotal role of CNT-based self-powered sensors in driving next-generation autonomous monitoring technologies and offers insights for the implementation of such sensors in practical biomedical and environmental applications. Full article

(This article belongs to the Special Issue Application of Carbon Nanotubes in Sensing)

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18 pages, 1456 KB

Open AccessArticle

Eu-Doped Nickelate as a Platform for an Enzyme-Based Resistive Biosensor for Glucose

by Gilson P. Lopes, Jéssica H. H. Rossato, Neftali L. V. Carreno, Iseli L. Nantes and Marcia T. Escote

Chemosensors 2025, 13(11), 387; https://doi.org/10.3390/chemosensors13110387 - 3 Nov 2025

Cited by 1 | Viewed by 638

Abstract

Nickelate oxides show promise for biosensing applications, especially in glucose detection. Creating nickelate-based biosensors involves utilizing their electron-correlated structure and the metal–insulator (MI) transition, which endows them with unique electronic, magnetic, and catalytic properties. Chemical or oxygen vacancies can alter their conductivity and [...] Read more.

Nickelate oxides show promise for biosensing applications, especially in glucose detection. Creating nickelate-based biosensors involves utilizing their electron-correlated structure and the metal–insulator (MI) transition, which endows them with unique electronic, magnetic, and catalytic properties. Chemical or oxygen vacancies can alter their conductivity and catalytic activity, enabling redox-based detection. In this study, Nd_1−xEu_xNiO₃ films (0 < x < 0.35) functionalized with Glucose Oxidase (GOx) were tested for glucose sensing. Eu substitution shifts the MI transition temperature (T_MI) from 200 K (x = 0) to 340 K (x = 35). At room temperature, these films undergo a metallic-to-insulator phase transition, which, along with the Ni³⁺/Ni²⁺ ratios, influences their sensing capabilities. Time-resolved electrical resistance measurements monitored how glucose interacts with the film surfaces. The sample with x = 0.3 exhibited a measurable resistance change in response to glucose concentrations ranging from 10⁻¹² to 0.5 M, with a sensitivity of 9.1 mM⁻¹ and a limit of detection (LOD) of approximately 0.47 μM. Reproducibility and interference tests with other sugars yielded good results across all samples. Eu doping in NdNiO₃ enhances their sensing response, highlighting the importance of electronic state and MI transition in the sensing performance of these nickelate-based glucose sensors. Full article

(This article belongs to the Special Issue Chemical Sensors for Bio-Medical and Environmental Applications, 2nd Edition)

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28 pages, 2438 KB

Open AccessReview

MOF-Derived Catalytic Interfaces for Low-Temperature Chemiresistive VOC Sensing in Complex Backgrounds

by Lu Zhang, Shichao Zhao, Jiangwei Zhu and Li Fu

Chemosensors 2025, 13(11), 386; https://doi.org/10.3390/chemosensors13110386 - 3 Nov 2025

Viewed by 1618

Abstract

The detection of volatile organic compounds (VOCs) at low operating temperatures is critical for public health, environmental monitoring, and industrial safety, yet it remains a significant challenge for conventional sensor technologies. Metal-organic frameworks (MOFs) have emerged as highly versatile precursors for creating advanced [...] Read more.

The detection of volatile organic compounds (VOCs) at low operating temperatures is critical for public health, environmental monitoring, and industrial safety, yet it remains a significant challenge for conventional sensor technologies. Metal-organic frameworks (MOFs) have emerged as highly versatile precursors for creating advanced sensing materials. This review critically examines the transformation of MOFs into functional catalytic interfaces for low-temperature chemiresistive VOC sensing. We survey the key synthetic strategies, with a focus on controlled pyrolysis, that enable the conversion of insulating MOF precursors into semiconducting derivatives with tailored porosity, morphology, and catalytically active sites. This review establishes the crucial synthesis-structure-performance relationships that govern sensing behavior, analyzing how factors like calcination temperature and precursor composition dictate the final material’s properties. We delve into the underlying chemiresistive sensing mechanisms, supported by evidence from advanced characterization techniques such as in situ DRIFTS and density functional theory (DFT) calculations, which elucidate the role of oxygen vacancies and heterojunctions in enhancing low-temperature catalytic activity. A central focus is placed on the persistent challenges of achieving high selectivity and robust performance in complex, real-world environments. We critically evaluate and compare strategies to mitigate interference from confounding gases and ambient humidity, including intrinsic material design and extrinsic system-level solutions like sensor arrays coupled with machine learning. Finally, this review synthesizes the current state of the art, identifies key bottlenecks related to stability and scalability, and provides a forward-looking perspective on emerging frontiers, including novel device architectures and computational co-design, to guide the future development of practical MOF-derived VOC sensors. Full article

(This article belongs to the Special Issue Detection of Volatile Organic Compounds in Complex Mixtures)

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30 pages, 3133 KB

Open AccessReview

Functional Solid–Liquid Interfaces for Electrochemical Blood Glucose Sensing: New Insights and Future Prospects

by Zarish Maqbool, Nadeem Raza, Azra Hayat, Mostafa E. Salem and Muhammad Faizan Nazar

Chemosensors 2025, 13(11), 385; https://doi.org/10.3390/chemosensors13110385 - 3 Nov 2025

Cited by 1 | Viewed by 1480

Abstract

Blood glucose monitoring is essential for the treatment of diabetes, a chronic disease that affects millions of people worldwide. Non-electrochemical blood glucose sensors often lack sensitivity and selectivity, especially in complex biological fluids, and are not suitable for wearable point-of-care devices. Electrochemical blood [...] Read more.

Blood glucose monitoring is essential for the treatment of diabetes, a chronic disease that affects millions of people worldwide. Non-electrochemical blood glucose sensors often lack sensitivity and selectivity, especially in complex biological fluids, and are not suitable for wearable point-of-care devices. Electrochemical blood glucose sensors, on the other hand, are easy to handle, inexpensive, and offer high sensitivity and selectivity even in the presence of interfering molecules. They can also be seamlessly integrated into wearable devices. This review explores the key blood glucose technologies, emphasizing the operating principle and classification of electrochemical glucose sensors. It also highlights the role of functional solid–liquid interfaces in optimizing sensor performance. Recent developments in solid–liquid interfacial materials, including metal-based, metal oxide-based, carbon-based, nanoparticle-based, conductive polymer, and graphene-based interfaces, are systematically analyzed for their sensing potential. Furthermore, this review highlights existing patents, the evolving market landscape, and data from clinical studies that bridge the gap between laboratory research and commercial application. Finally, we present future perspectives and highlight the need for next-generation wearable and enzyme-free glucose sensors for continuous and non-invasive glucose monitoring. Full article

(This article belongs to the Special Issue Electrochemical Sensors and Biosensors: Recent Advances and Future Challenges)

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14 pages, 4492 KB

Open AccessArticle

The Effect of ortho/meta/para-Substitution of a Phenyl Group on the AIPE and TNP-Sensing Properties of Ir(III) Complexes

by Xiaoran Yang, Jiahao Du, Qinglong Zhang, Liyan Zhang and Chun Liu

Chemosensors 2025, 13(11), 384; https://doi.org/10.3390/chemosensors13110384 - 1 Nov 2025

Viewed by 494

Abstract

Three Ir(III) complexes 1–3 were synthesized using phenyl-modified 2-phenylpyridine derivatives as the cyclometalating ligands. All complexes exhibited aggregation-induced phosphorescence emission (AIPE) in CH₃CN/H₂O, which facilitated highly sensitive detection of 2,4,6-trinitrophenol (TNP). Among them, complex 3 containing a [...] Read more.

Three Ir(III) complexes 1–3 were synthesized using phenyl-modified 2-phenylpyridine derivatives as the cyclometalating ligands. All complexes exhibited aggregation-induced phosphorescence emission (AIPE) in CH₃CN/H₂O, which facilitated highly sensitive detection of 2,4,6-trinitrophenol (TNP). Among them, complex 3 containing a phenyl group at the para-position of the phenyl moiety in 2-phenylpyridine showed superior detection performance with the limit of detection (LOD) of 74 nM. 1–3 demonstrated excellent anti-interference and selectivity performances for the detection of TNP in different common water samples. In addition, ¹H NMR spectra, density functional theory calculations, and spectroscopic results indicate that the detection mechanism for TNP is attributed to the combined effects of photo-induced electron transfer and the inner-filter effect. Full article

(This article belongs to the Special Issue Recent Advances in Chemical Sensors for Biological Detection and Environmental Monitoring: Fundamental Science and Applications)

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16 pages, 1334 KB

Open AccessArticle

Development of a Paper-Based Electrochemical Immunosensor for Cardiac Troponin I Determination Using Gold Nanoparticle-Modified Screen-Printed Electrodes

by Mayra Asevedo Campos de Resende, Ana Elisa Ferreira Oliveira, Thaís Cristina de Oliveira Cândido, Daniela Nunes da Silva, Scarlat Ohanna Dávila da Trindade, Lucas Franco Ferreira and Arnaldo César Pereira

Chemosensors 2025, 13(11), 383; https://doi.org/10.3390/chemosensors13110383 - 31 Oct 2025

Cited by 1 | Viewed by 1317

Abstract

Acute Myocardial Infarction (AMI) is a critical cardiac condition that poses a substantial threat to myocardial function. Expedient diagnosis of AMI is paramount and relies on serological assays for rapid and accurate quantification of relevant biomarkers. Electrochemical sensors have emerged as promising candidates [...] Read more.

Acute Myocardial Infarction (AMI) is a critical cardiac condition that poses a substantial threat to myocardial function. Expedient diagnosis of AMI is paramount and relies on serological assays for rapid and accurate quantification of relevant biomarkers. Electrochemical sensors have emerged as promising candidates for this application, owing to their accessibility, operational simplicity, and high specificity. In this study, we developed a paper-based electrochemical immunosensor to detect cardiac troponin I in serum and saliva specimens. The electrode was fabricated using screen-printing technology with photographic paper as the substrate, employing graphite-based ink, nail polish, and acetone as the solvent. A quasi-reference electrode was constructed using silver powder-based ink, nail polish, and acetone. The immunosensor was prepared by modifying the working electrode with gold nanoparticles (AuNP) functionalized with cardiac troponin I antibodies (anti-cTnI) and bovine serum albumin (BSA). This modified electrode was subsequently used to detect the troponin I antigen. The analyses were performed in 0.1 mol L⁻¹ phosphate buffer medium, pH 7.00, in the presence of 5.0 mmol L⁻¹ of the potassium ferrocyanide probe. The immunosensor exhibited a sensitivity of 0.006 µA/fg mL⁻¹, a limit of detection of 9.83 fg mL⁻¹, and a limit of quantification of 32.79 fg mL⁻¹. Specificity studies conducted in the presence of other macromolecules demonstrated minimal interference, with relative standard deviations (RSD) below 5.00%, indicating a specific interaction with troponin I. Furthermore, the immunosensor demonstrated excellent reproducibility and stability. Upon application to serum and saliva samples, the immunosensor presented recoveries of approximately 99–105%, suggesting its potential applicability in clinical analyses. Full article

(This article belongs to the Special Issue Advanced Sensing Materials for Disease, Health and Environment Analysis)

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18 pages, 1971 KB

Open AccessArticle

Spectrofluorometric and Colorimetric Determination of Gliquidone: Validation and Sustainability Assessments

by Lateefa A. Al-Khateeb, Yasmeen G. Abou El-Reash, Abdullah N. Alotaibi, Nuha Y. Elamin, Nouruddin W. Ali, Hala E. Zaazaa, Mohamed Abdelkawy, Maimana A. Magdy and Mohammed Gamal

Chemosensors 2025, 13(11), 382; https://doi.org/10.3390/chemosensors13110382 - 30 Oct 2025

Viewed by 711

Abstract

Two novel, simple, and sensitive methods for the assay of Gliquidone (GLI) were developed and validated in various matrices, including raw material, Glurenor^®® tablets, and spiked human plasma (spectrofluorometric approach only). The first method employs spectrofluorimetry to measure GLI fluorescence emission at [...] Read more.

Two novel, simple, and sensitive methods for the assay of Gliquidone (GLI) were developed and validated in various matrices, including raw material, Glurenor^®® tablets, and spiked human plasma (spectrofluorometric approach only). The first method employs spectrofluorimetry to measure GLI fluorescence emission at 404 nm upon excitation at 311 nm, using a solvent mixture of phosphate buffer (pH 4), β-cyclodextrin, and methanol. The second one was colorimetric, based on GLI’s reaction with 7,7,8,8-tetracyanoquinodimethane (TCNQ) in acetone, forming a stable colored product whose absorbance was quantitatively measured at 745.5 nm. The spectrofluorometric approach showed a linear range of 0.05–0.45 µg·mL⁻¹ with a mean recovery of 100.43 ± 0.88%, while the colorimetric method demonstrated a broader linear range (20–200 µg·mL⁻¹) and mean recovery of 101.10 ± 1.27%. GLI and TCNQ react in a 1:1 ratio at 1.7 × 10⁻² M concentrations. Both methods were successfully applied without excipient interference. Sustainability, practicality, and performance (validation) assessments (AGREE, BAGI, and RAPI) favored the spectrofluorometric method due to higher sensitivity, a broader working range, lower detection limits, and better overall practical and environmental performance. In conclusion, the spectrofluorometric approach offers high sensitivity and precision, while the colorimetric one provides a wider linear range and greater complex stability. Full article

(This article belongs to the Section Analytical Methods, Instrumentation and Miniaturization)

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18 pages, 3329 KB

Open AccessReview

Bionic Sensing and BCI Technologies for Olfactory Improvement and Reconstruction

by Yajie Zhang, Qifei Wang, Fan Wu, Qin Yang, Xinrui Tang, Shunuo Shang, Sunhong Hu, Guojin Zhou and Liujing Zhuang

Chemosensors 2025, 13(11), 381; https://doi.org/10.3390/chemosensors13110381 - 29 Oct 2025

Cited by 1 | Viewed by 1529

Abstract

Olfactory dysfunction (OD) is an early symptom associated with a variety of diseases, including COVID-19, Alzheimer’s disease, and Parkinson’s disease, where patients commonly experience hyposmia or anosmia. Effective restoration of olfactory function is therefore crucial for disease diagnosis and management, and improving overall [...] Read more.

Olfactory dysfunction (OD) is an early symptom associated with a variety of diseases, including COVID-19, Alzheimer’s disease, and Parkinson’s disease, where patients commonly experience hyposmia or anosmia. Effective restoration of olfactory function is therefore crucial for disease diagnosis and management, and improving overall quality of life. Traditional treatment approaches have primarily relied on medication and surgical intervention. However, recent advances in bionic sensing and brain–computer interface (BCI) technologies have opened up novel avenues for olfactory rehabilitation, facilitating the reconstruction of neural circuits and the enhancement of connectivity within the central nervous system. This review provides an overview of the current research landscape on OD-related diseases and highlights emerging olfactory restoration strategies, including olfactory training (OT), electrical stimulation, neural regeneration, and BCI-based approaches. These developments lay a theoretical foundation for achieving more rapid and reliable clinical recovery of olfactory function. Full article

(This article belongs to the Special Issue Advancements of Chemosensors and Biosensors in China—2nd Edition)

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38 pages, 8463 KB

Open AccessArticle

Networked Low-Cost Sensor Systems for Urban Air Quality Monitoring: A Long-Term Use-Case in Bari (Italy)

by Michele Penza, Domenico Suriano, Valerio Pfister, Sebastiano Dipinto, Mario Prato and Gennaro Cassano

Chemosensors 2025, 13(11), 380; https://doi.org/10.3390/chemosensors13110380 - 28 Oct 2025

Viewed by 1286

Abstract

A sensor network based on 10 stationary nodes distributed in Bari (Southern Italy) has been deployed for urban air quality (AQ) monitoring. The low-cost sensor systems have been installed in specific sites (e.g., buildings, offices, schools, streets, ports, and airports) to enhance environmental [...] Read more.

A sensor network based on 10 stationary nodes distributed in Bari (Southern Italy) has been deployed for urban air quality (AQ) monitoring. The low-cost sensor systems have been installed in specific sites (e.g., buildings, offices, schools, streets, ports, and airports) to enhance environmental awareness of the citizens and to supplement the expensive official air-monitoring stations with cost-effective sensor nodes at high spatial and temporal resolution. Continuous measurements were performed by low-cost electrochemical gas sensors (CO, NO₂, O₃), optical particle counter (PM₁₀), and NDIR infrared sensor (CO₂), including micro-sensors for temperature and relative humidity. The sensors are operated to assess the performance during a campaign (July 2015–December 2017) of several months for citizen science in sustainable smart cities. Typical values of CO₂, measured by distributed nodes, varied from 312 to 494 ppm (2016), and from 371 to 527 ppm (2017), depending on seasonal micro-climate change and site-specific conditions. The results of the AQ-monitoring long-term campaign for selected sensor nodes are presented with a relative error of 26.2% (PM₁₀), 21.7% (O₃), 25.5% (NO₂), and 79.4% (CO). These interesting results suggest a partial compliance, excluding CO, with Data Quality Objectives (DQO) by the European Air Quality Directive (2008/50/EC) for Indicative (Informative) Measurements. Full article

(This article belongs to the Special Issue Recent Advances in Low-Cost Chemical Sensor Technologies for Environmental Monitoring Applications)

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15 pages, 2204 KB

Open AccessArticle

Electrochemical DNA Biosensor for Detection of Hepatitis C Virus Using a 3D Poly-L-Lysine/Carbon Nanotube Film

by Gilvânia M. Santana, Anna P. O. Souza, Erika K. G. Trindade, Stephen R. Benjamin and Rosa Fireman Dutra

Chemosensors 2025, 13(11), 379; https://doi.org/10.3390/chemosensors13110379 - 28 Oct 2025

Viewed by 786

Abstract

Hepatitis C represents a critical global health crisis, causing approximately 1.4 million deaths annually. Although 98% of cases are treatable, only about 20% of infected individuals know their hepatitis C virus (HCV) status, highlighting the urgent need for rapid and more efficient diagnostic [...] Read more.

Hepatitis C represents a critical global health crisis, causing approximately 1.4 million deaths annually. Although 98% of cases are treatable, only about 20% of infected individuals know their hepatitis C virus (HCV) status, highlighting the urgent need for rapid and more efficient diagnostic management. Viral genetic material can be detected in serum or plasma within just one week of exposure, making it the most reliable marker and the gold standard for active HCV infection diagnosis. In this study, a biosensor was developed to detect conserved nucleotide sequences of HCV using a 3D surface electrode composed of poly-L-lysine (PLL) and carbon nanotubes (CNTs). PLL is a positively charged biocompatible polymer rich in amine groups, attractive for the immobilization of proteins, DNA, and other biomolecules. PLL was employed to construct a 3D surface with vertically aligned CNTs, achieving a high electron transfer rate. Cyclic voltammetry technique and scanning electron microscopy (SEM) were used to characterize the sensor platform, and analytical responses were measured by differential pulse voltammetry. This HCV biosensor detected the hybridization event by a significant reduction in DPV peaks in the presence of the ferri/ferrocyanide redox probe, without any intercalator agents. DNA responses were observed in phosphate-buffered saline (PBS) and cDNA-spiked serum samples, demonstrating its analytical specificity. These findings represent advances in analytical tools that can effectively address the challenges of timely diagnosis for asymptomatic HCV carriers. Full article

(This article belongs to the Special Issue Application of Carbon Nanotubes in Sensing)

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13 pages, 2392 KB

Open AccessArticle

Construction of Cr-MIL-101@PEDOT/MIP Composite Functionalized Glassy Carbon Electrode for PFOS Electrochemical Detection

by Jingru Liang, Haiying Ming, Yijun Meng, Qingyun Tian, Baoyang Lu, Chuanyi Wang, Haijun Du and Shuai Chen

Chemosensors 2025, 13(11), 378; https://doi.org/10.3390/chemosensors13110378 - 27 Oct 2025

Viewed by 829

Abstract

Perfluorooctanesulfonate (PFOS) is a typical persistent organic pollutant, which presents a significant risk to the ecosystem and human health. Therefore, the development of a highly sensitive and effective detection technique for PFOS has aroused wide concern. In this study, for the mesoporous metal–organic [...] Read more.

Perfluorooctanesulfonate (PFOS) is a typical persistent organic pollutant, which presents a significant risk to the ecosystem and human health. Therefore, the development of a highly sensitive and effective detection technique for PFOS has aroused wide concern. In this study, for the mesoporous metal–organic frameworks (MOFs), Cr-MIL-101 were used as the precursor. And the poly(3,4-ethylenedioxythiophene) (PEDOT) using as molecularly imprinted polymers (MIPs) was loaded on Cr-MIL-101 to form a core–shell structure. The obtained Cr-MIL-101@PEDOT/MIP composites integrate the high specific surface area of Cr-MIL-101 and the specific recognition capability of PEDOT/MIP. The glassy carbon electrode (GCE) interface modified by them can specifically adsorb PFOS through electrostatic interactions, coordination by Cr metal nodes, hydrophobic interaction, and hydrogen bonding, etc. The adsorbed PFOS molecules could block the active sites at the electrode interface, causing the current decay of the redox probe. Following the quantitative analysis of peak current decay values using the Langmuir model and the Freundlich–Langmuir model, a wide detection range (0.1–200 nM) and a low detection limit (0.025 nM) were obtained. Characterization techniques including scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), X-ray photoelectron spectroscopy (XPS), and electrochemical methods were employed to validate the fabrication of the composites. Moreover, Cr-MIL-101@PEDOT/MIP/GCE showed satisfactory stability, repeatability, and selectivity, providing an effective method for the detection of PFOS in practical samples, showing a wide prospective application. Full article

(This article belongs to the Special Issue Application of Organic Conjugated Materials in Chemosensors)

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21 pages, 3317 KB

Open AccessArticle

Microcontact-Printed Flexible Electrodes for Label-Free Electrochemical Detection of Lung Cancer Biomarker

by Alberto G. Silva-Junior, Abdelhamid Errachid, Nadia Zine, Marie Hangouet, Guy Raffin, Michelly C. Pereira, Maria D. L. Oliveira and Cesar A. S. Andrade

Chemosensors 2025, 13(11), 377; https://doi.org/10.3390/chemosensors13110377 - 27 Oct 2025

Viewed by 1032

Abstract

Lung cancer remains one of the deadliest cancers worldwide, which highlights the urgent need for new diagnostic tools to detect reliable biomarkers. To enable scalable and cost-effective production, we developed reusable PDMS stamps patterned with electrodes to print flexible electrodes on PET substrates [...] Read more.

Lung cancer remains one of the deadliest cancers worldwide, which highlights the urgent need for new diagnostic tools to detect reliable biomarkers. To enable scalable and cost-effective production, we developed reusable PDMS stamps patterned with electrodes to print flexible electrodes on PET substrates using a microcontact printing (µCP) approach. PET was chosen not only for its flexibility but also as a more sustainable alternative to conventional rigid materials. On these electrodes, three sensing platforms were tested for neuron-specific enolase (NSE) detection: APTES-based monolayers, electrospun PVA/alginate nanofibers, and electropolymerized polypyrrole (PPy) films. Voltammetric and fluorescence/AFM analyses confirmed that all three platforms could recognize the target analyte, with the PPy-CdTe configuration showing the strongest signal variation. Impedance spectroscopy further supported this finding, revealing a clear linear correlation between charge transfer resistance (RCT) and NSE concentration. The PPy-CdTe sensor demonstrated high sensitivity and consistent performance for NSE detection, achieving a detection limit (LOD) of 8.05 pg·µL⁻¹ and a quantification limit (LOQ) of 26.84 pg·µL⁻¹. Full article

(This article belongs to the Special Issue Advanced Biosensors for Diagnostic Applications)

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13 pages, 1813 KB

Open AccessArticle

Highly Selective and Stable Electrochemical Sensor for Hydrogen Peroxide—Application in Cosmetics Quality Control

by Totka Dodevska, Dobrin Hadzhiev and Nina Dimcheva

Chemosensors 2025, 13(11), 376; https://doi.org/10.3390/chemosensors13110376 - 25 Oct 2025

Viewed by 954

Abstract

Nowadays, electrochemical sensors have become a popular topic in cosmetics quality control. A simple and stable electrochemical sensor for hydrogen peroxide (H₂O₂) was developed on the basis of a rhodium-modified glassy carbon electrode (Rh/GCE). A quick, one-step, reproducible, and [...] Read more.

Nowadays, electrochemical sensors have become a popular topic in cosmetics quality control. A simple and stable electrochemical sensor for hydrogen peroxide (H₂O₂) was developed on the basis of a rhodium-modified glassy carbon electrode (Rh/GCE). A quick, one-step, reproducible, and cost-effective electrodeposition procedure was applied to modify GCE with Rh nanoparticles. The sensor shows a high selectivity for H₂O₂ at a low applied potential of −0.1 V (vs. Ag/AgCl, 3 M KCl), with an excellent stability and good repeatability (RSD = 3.2%; n = 5). The modified electrode Rh/GCE demonstrates a high sensitivity of 172.24 ± 1.95 μA mM⁻¹ cm⁻² (n = 3), a linear response to H₂O₂ between 5 and 1000 µM, and a detection limit estimated to be 1.2 µM. Furthermore, Rh/GCE has been successfully used to measure H₂O₂ concentrations in hair dye and antiseptic solution, yielding satisfactory recovery rates. These findings highlight the potential of the Rh/GCE for the reliable quantitative detection of H₂O₂ in complex cosmetics matrices. Full article

(This article belongs to the Special Issue Nanostructured Materials for Electrochemical Sensing)

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13 pages, 648 KB

Open AccessArticle

Environmental Sustainability Study for the Determination of Ketoprofen in the Presence of Its Main Photo-Degradation Products in River Water Using Solid-Contact Electrodes

by Ali Altharawi and Sherif A. Abdel-Gawad

Chemosensors 2025, 13(11), 375; https://doi.org/10.3390/chemosensors13110375 - 24 Oct 2025

Viewed by 710

Abstract

A major objective in recent years has been the use of membrane sensors for the purpose of monitoring and recognizing environmental pollutants in pharmaceuticals. Ketoprofen (KTP) is likely to be found in the environment, particularly in surface water bodies like rivers, because of [...] Read more.

A major objective in recent years has been the use of membrane sensors for the purpose of monitoring and recognizing environmental pollutants in pharmaceuticals. Ketoprofen (KTP) is likely to be found in the environment, particularly in surface water bodies like rivers, because of its extensive use in medicine. The photodegradability of KTP and the prolonged exposure of river water to sunlight may facilitate its photodegradation. To measure KTP along with its main photo-degradation products, three membrane electrodes were fabricated using different plasticizers. Dioctyl phthalate (DOP), dibutyl sebacate (DBS), and o-nitrophenyloctyl ether (o-NPOE) membrane electrodes were constructed for the selective analysis of the investigated medication. The fabricated sensors were prepared using tetraoctyl ammonium chloride as an ion-pairing agent. A linear range of 1 × 10⁻⁵ M to 1 × 10⁻¹ M was shown by the electrodes. The slopes (in mV/decade) for the DOP, DBS, and o-NPOE membranes were −58.80 ± 0.90, −57.90 ± 0.80, and −56.80 ± 1.10, respectively. All test parameters were refined to enhance electrochemical performance. The synthesized membranes were successfully utilized to accurately measure KTP amidst its primary photodegradants. The fabricated sensors were effectively utilized to measure KTP in river water samples without requiring pre-treatment processes. Full article

(This article belongs to the Special Issue Low-Cost Chemosensors for Applications in Environment, Health, Food, and Industry Process Control, 2nd Edition)

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