Chemosensors

31 pages, 952 KiB

Open AccessReview

Electronic Tongue Technology Applied to the Analysis of Grapes and Wines: A Comprehensive Review from Its Origins

by Celia Garcia-Hernandez, Cristina Garcia-Cabezon, Maria Luz Rodriguez-Mendez and Fernando Martin-Pedrosa

Chemosensors 2025, 13(5), 188; https://doi.org/10.3390/chemosensors13050188 (registering DOI) - 17 May 2025

Abstract

The electronic tongue (ET) and bioelectronic tongue (bioET) technologies have emerged as innovative and promising tools for the characterization and quality control of complex liquid matrices such as grape musts and wines. These multisensor systems, based on electrochemical detection and chemometric analysis, provide [...] Read more.

The electronic tongue (ET) and bioelectronic tongue (bioET) technologies have emerged as innovative and promising tools for the characterization and quality control of complex liquid matrices such as grape musts and wines. These multisensor systems, based on electrochemical detection and chemometric analysis, provide global and rapid information about taste-related attributes, antioxidant content, and other critical parameters, offering an alternative or complement to traditional analytical methods. This review explores the principles, development, and applications of ET and bioET in the wine industry, highlighting their capacity to assess grape ripeness, monitor fermentation, determine wine aging, detect adulterations, and support geographical and varietal authentication. Special attention is paid to advances in sensing materials—such as conducting polymers, metal nanoparticles, and enzymes—and the construction techniques of sensors and biosensors, which have improved ET performance. Finally, the potential of these technologies as cost-effective, portable, and on-site tools aligns with the demands of Industry 4.0 and next-generation smart agriculture and food production systems. Full article

(This article belongs to the Special Issue Applications of Electronic Nose (E-Nose) and Electronic Tongue (E-Tongue) in Food Quality)

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16 pages, 835 KiB

Open AccessArticle

Monitoring the Olfactory Evolution of Cold-Fermented Sourdough Using an Electronic Nose

by Elisabetta Poeta, Estefanía Núñez-Carmona, Veronica Sberveglieri, Jesús Lozano and Ramiro Sánchez

Chemosensors 2025, 13(5), 187; https://doi.org/10.3390/chemosensors13050187 (registering DOI) - 17 May 2025

Abstract

The quality of artisanal bread is strongly influenced by sourdough fermentation, where aroma development and microbial stability are key factors. This study evaluates the use of an electronic nose (E-nose) to monitor cold fermentation, integrating it with microbiological analysis and gas chromatography–mass spectrometry [...] Read more.

The quality of artisanal bread is strongly influenced by sourdough fermentation, where aroma development and microbial stability are key factors. This study evaluates the use of an electronic nose (E-nose) to monitor cold fermentation, integrating it with microbiological analysis and gas chromatography–mass spectrometry (SPME-GC-MS) to characterize the dough’s volatile profile. A clear correlation was observed between microbial dynamics, pH reduction (from 5.8 to 3.8), and the evolution of volatile compounds, with notable increases in acetic acid (up to 12.75%), ethanol (11.95%), and fruity esters such as isoamyl acetate (33.33%). Linear discriminant analysis (LDA) explained 96.31% of the total variance in a single component, successfully separating the fermentation stages. An artificial neural network discriminant analysis (ANNDA) model achieved 95% accuracy in the validation phase. These results confirm the E-nose’s ability to track biochemical transformations in real time and identify optimal fermentation points. This approach enhances quality control and sensory standardization in sourdough-based bakery products. Full article

(This article belongs to the Special Issue Sensors for Food Testing, Environmental Analysis, and Medical Diagnostics)

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15 pages, 1461 KiB

Open AccessArticle

Detection of Oral Beta-Lactam Antibiotics Using a Taste Sensor with Surface-Modified Lipid/Polymer Membranes

by Takahiro Uchida, Ziyi Jiang, Zeyu Zhao, Shunsuke Kimura, Takeshi Onodera and Kiyoshi Toko

Chemosensors 2025, 13(5), 186; https://doi.org/10.3390/chemosensors13050186 - 16 May 2025

Abstract

In our previous study, a taste sensor modified with 3-bromo-2,6-dihydroxybenzoic acid (3-Br-2,6-DHBA) exhibited significant responses to xanthine-based substances, suggesting an allosteric detection mechanism. This study investigates the potential of the 3-Br-2,6-DHBA-modified sensor membrane for detecting other drug classes. Eleven structurally diverse drugs—including caffeine, [...] Read more.

In our previous study, a taste sensor modified with 3-bromo-2,6-dihydroxybenzoic acid (3-Br-2,6-DHBA) exhibited significant responses to xanthine-based substances, suggesting an allosteric detection mechanism. This study investigates the potential of the 3-Br-2,6-DHBA-modified sensor membrane for detecting other drug classes. Eleven structurally diverse drugs—including caffeine, antibiotics, antivirals, analgesic-antipyretics from the WHO Model List of Essential Medicines for Children—were tested, as they were previously undetectable by a conventional bitterness sensor. Among them, amoxicillin, an oral broad-spectrum penicillin, and cefalexin, an oral cephalosporin, elicited significantly higher sensor responses when 3-Br-2,6-DHBA-modified membrane was used. To further examine this response, experiments were conducted using membranes modified with 3-Br-2,6-DHBA, 2,6-dihydroxybenzoic acid (2,6-DHBA), and benzoic acid. These tests confirmed that only 3-Br-2,6-DHBA-modified membrane produced significant responses to amoxicillin and cefalexin, suggesting that hydroxyl groups in 3-Br-2,6-DHBA contribute to allosteric effects via hydrogen bonding. Additional tests demonstrated higher responses for cefaclor and cefdinir, both oral cephalosporins. The interaction between 3-Br-2,6-DHBA and the beta-lactam ring, as well as adjacent five- or six-membered rings in amoxicillin and several oral cephalosporins, likely enables allosteric detection by stacking via π electron, hydrophobilc interaction, and hydrogen bonding. In conclusion, the 3-Br-2,6-DHBA-modified sensor membrane effectively detects amoxicillin and oral cephalosporins via allosteric mechanism. Full article

(This article belongs to the Special Issue Innovative Analytical Methods in Pharmaceutical and Biomedical Analysis)

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15 pages, 5448 KiB

Open AccessArticle

Disposable Electrochemical Serotonin Biosensor Based on the Nanocomposite of Carbon Nanotubes

by Ryang-Hyeon Kim, Won-Yong Jeon, Tae-Won Seo and Young-Bong Choi

Chemosensors 2025, 13(5), 185; https://doi.org/10.3390/chemosensors13050185 - 16 May 2025

Abstract

A PAAc-PVI(4:1)@MWCNT hybrid was synthesized for the selective electrochemical detection of serotonin. Multi-walled carbon nanotubes (MWCNT) enhanced electrode conductivity, while the hydrophilic polymer Poly(Acrylic Acid-co-Vinyl imidazole) (PAAc-PVI) facilitated serotonin recognition. At pH 7.4, the carboxyl (-COO⁻) groups in PAAc-PVI interacted with [...] Read more.

A PAAc-PVI(4:1)@MWCNT hybrid was synthesized for the selective electrochemical detection of serotonin. Multi-walled carbon nanotubes (MWCNT) enhanced electrode conductivity, while the hydrophilic polymer Poly(Acrylic Acid-co-Vinyl imidazole) (PAAc-PVI) facilitated serotonin recognition. At pH 7.4, the carboxyl (-COO⁻) groups in PAAc-PVI interacted with the amine (-NH₃⁺) groups of serotonin, enabling oxidation and electron transfer for signal detection. Additionally, π-π interactions between vinylimidazole and MWCNT improved dispersion and stability. The hybrid materials enhanced electron transfer efficiency, increasing sensitivity and reliability. Structural and electrochemical properties were characterized using FT-IR, HR-TEM, TGA, Raman spectroscopy, impedance analysis, and differential pulse voltammetry (DPV). Serotonin detection using the fabricated electrode demonstrated high selectivity (LOD 0.077 μM and LOQ 0.26 μM), reproducibility (%RSD 1X PBS condition (4.63%) and human serum condition (4.81%)), and quantitative capability (dynamic range 1.2 μM to 10.07 μM) without interference (potential shift from +0.40 V to −0.15 V) from blood-based substances, confirming its potential for electrochemical biosensing applications. Full article

(This article belongs to the Special Issue Advanced Nanomaterials-Based (Bio)sensors for Electrochemical Detection and Analysis)

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28 pages, 7901 KiB

Open AccessReview

Research Progress of Rare Earth Metal–Organic Frameworks on Pollutant Monitoring

by Qingbo Yu, Meng Wang, Xiujuan Feng and Xianhui Li

Chemosensors 2025, 13(5), 184; https://doi.org/10.3390/chemosensors13050184 - 15 May 2025

Abstract

Rare earth metal–organic frameworks (RE-MOFs) are mainly composed of rare earth ions and organic ligands, taking advantage of the strengths of both metal–organic frameworks (MOFs) and rare earth ions. Rare earth ions have the unique feature of unfilled 4f electron shells, which endows [...] Read more.

Rare earth metal–organic frameworks (RE-MOFs) are mainly composed of rare earth ions and organic ligands, taking advantage of the strengths of both metal–organic frameworks (MOFs) and rare earth ions. Rare earth ions have the unique feature of unfilled 4f electron shells, which endows them with higher coordination numbers, unique luminescence properties, larger Stokes shifts, longer fluorescence lifetimes, and higher luminescence quantum efficiency. The MOFs combined with a variety of organic ligands can effectively guide the antenna effect to sensitize the rare earth ions and thus enhance the photon emission, making RE-MOFs a promising material in the field of fluorescent probes. In this paper, the recent advances in design principles, strategies, synthesis means, and monitoring mechanisms of RE-MOF materials for pollutant monitoring are presented. The intrinsic correlation between the luminescence performance of RE-MOFs, the detection of contaminants and the selection of organic ligands, and the adjustment of the MOF backbone structure is systematically and comprehensively discussed. Finally, the future development direction and application prospects of RE-MOF materials are summarized and discussed. Full article

(This article belongs to the Section Nanostructures for Chemical Sensing)

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40 pages, 8838 KiB

Open AccessReview

Revolutionizing Electrochemical Sensing with Nanomaterial-Modified Boron-Doped Diamond Electrodes

by Pramod K. Gupta and James R. Siegenthaler

Chemosensors 2025, 13(5), 183; https://doi.org/10.3390/chemosensors13050183 - 14 May 2025

Viewed by 170

Abstract

Nanomaterial advancements have heralded a new era in electrochemical sensing by enabling the precise modification of boron-doped diamond (BDD) electrodes. This review investigates recent remarkable advances, challenges, and potential future directions of nanomaterial-modified BDD electrodes for biosensing applications, emphasizing their game-changing potential. This [...] Read more.

Nanomaterial advancements have heralded a new era in electrochemical sensing by enabling the precise modification of boron-doped diamond (BDD) electrodes. This review investigates recent remarkable advances, challenges, and potential future directions of nanomaterial-modified BDD electrodes for biosensing applications, emphasizing their game-changing potential. This review begins by investigating the intrinsic properties of boron-doped diamond electrodes, emphasizing their inherent advantages in electrochemical biosensing. Following that, it embarks on an illuminating journey through the spectrum of nanomaterials that have revolutionized these electrodes. These materials include carbon-based nanomaterials, metal and metal oxide nanostructures, their combinations, patterned nanostructures on BDDs, and other nanomaterials, each with unique properties that can be used to tailor BDD electrodes to specific applications. Throughout this article, we explain how these nanomaterials improve BDD electrodes, from accelerated electron transfer kinetics to increased surface area and sensitivity, promising unprecedented performance. Beyond experimentation, it investigates the challenges—stability, reproducibility, and scalability—associated with the use of nanomaterials in BDD electrode modifications, as well as the ecological and economic implications. Furthermore, the future prospects of nanomaterial-modified BDD electrodes hold the key to addressing pressing contemporary research challenges. Full article

(This article belongs to the Special Issue Recent Advances in Electrode Materials for Electrochemical Sensing)

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33 pages, 4183 KiB

Open AccessReview

Recent Advances on Fluorescent Sensors for Detection of Pathogenic Bacteria

by Xu Tang, Qi Qi, Binrong Li, Zhi Zhu, Jian Lu and Lei Liu

Chemosensors 2025, 13(5), 182; https://doi.org/10.3390/chemosensors13050182 - 13 May 2025

Viewed by 131

Abstract

Pathogenic bacteria are one of the main causes of diseases and have become an important public health problem threatening human health and socio-economic development. Therefore, it is particularly important to develop an efficient and convenient detection method. Fluorescence detection has become a highly [...] Read more.

Pathogenic bacteria are one of the main causes of diseases and have become an important public health problem threatening human health and socio-economic development. Therefore, it is particularly important to develop an efficient and convenient detection method. Fluorescence detection has become a highly concerned analytical technology, which has gradually emerged in the aspect of pathogen detection, and is favored by researchers. In this review, we summarized a series of sensing strategies for pathogen detection based on fluorescence response signals in recent years, including single molecule fluorescent probes, biosensors, nanocomposite sensors and strategies for integrating different recognition elements with nanomaterials, along with the advantages and disadvantages of various design strategies. Based on the existing research reports, the existing problems and future research challenges of fluorescent sensor technology are proposed. Full article

(This article belongs to the Special Issue Feature Review Papers in Chemical/Bio-Sensors and Analytical Chemistry in 2025)

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37 pages, 4556 KiB

Open AccessReview

Current Opportunities and Trends in the Gas Sensor Market: A Focus on e-Noses and Their Applications in Food Industry

by Selene Mor, Buse Gunay, Michele Zanotti, Michele Galvani, Stefania Pagliara and Luigi Sangaletti

Chemosensors 2025, 13(5), 181; https://doi.org/10.3390/chemosensors13050181 - 12 May 2025

Viewed by 324

Abstract

Electronic noses (e-noses) are devices developed to recognize/classify odors and used in many fields, matching the current societal needs and concerns, such as food integrity and quality control, environmental monitoring, medical diagnostics, safety, and security in urban and industrial settlements. In this study, [...] Read more.

Electronic noses (e-noses) are devices developed to recognize/classify odors and used in many fields, matching the current societal needs and concerns, such as food integrity and quality control, environmental monitoring, medical diagnostics, safety, and security in urban and industrial settlements. In this study, we review the application fields of e-noses based on a market analysis of currently available devices. A total of 44 companies active up to 2024, as well as 265 products, have been identified by considering the web pages of companies that feature e-noses among their products. These devices have been classified according to (i) the sensing mechanisms underlying the device performances and (ii) the application fields. The most diffused sensing devices/systems are chemiresistors (12.8%), electrochemical sensors (13.0%), catalytic beads (12.4%), and those based on optical detection techniques (16.0%). Commercial e-noses find large application in the industrial (21.0%) and chemical and petrochemical (21.0%) fields. A focus is made on the food and beverage application field, which is still a minor part of the overall share (6.0%) but is rapidly increasing and plays a relevant role in future applications where safety, sustainability, and quality issues are strictly intertwined. From this study, a rather complex picture emerges, and a proper taxonomy is expected to correctly classify the different kinds of e-noses. Full article

(This article belongs to the Special Issue Applications of Electronic Nose (E-Nose) and Electronic Tongue (E-Tongue) in Food Quality)

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20 pages, 6980 KiB

Open AccessArticle

Electrodeposition of Au Nanoparticles on 2D Layered Materials and Their Applications in Electrocatalysis of Nitrite

by Oana Elena Carp, Mirela-Fernanda Zaltariov, Mariana Pinteala and Adina Arvinte

Chemosensors 2025, 13(5), 180; https://doi.org/10.3390/chemosensors13050180 - 12 May 2025

Viewed by 190

Abstract

This study presents a comparative analysis of gold nanoparticles electrodeposited on different two-dimensional materials used as electrode substrates, graphene (Gr) and MoS₂, or co-deposited with the metallic material MoS₂. The morphological and electrochemical data demonstrate the efficiency of the [...] Read more.

This study presents a comparative analysis of gold nanoparticles electrodeposited on different two-dimensional materials used as electrode substrates, graphene (Gr) and MoS₂, or co-deposited with the metallic material MoS₂. The morphological and electrochemical data demonstrate the efficiency of the electrodeposition process and the preferability of gold nanoparticles for certain attachment sites depending on the nature of the material used as a substrate and the deposition method used. The electrocatalytic activity of the gold nanoparticles obtained in these configurations was evaluated via the oxidation of nitrite ions (NO₂⁻), using both qualitative and quantitative approaches, by cyclic voltammetry and amperometry techniques. The electrocatalytic activity of gold nanoparticles co-deposited with MoS₂ is superior compared to that of gold nanoparticles deposited either on bare gold electrodes or on 2D materials (graphene and MoS₂), showing good performance with a specific sensitivity of 1.043 μA µM⁻¹ cm⁻² on the linear range of 0.5–600 µM nitrite, with a limit of detection of 0.16 µM and good anti-interference ability. Full article

(This article belongs to the Special Issue Electrochemical Sensors and Biosensors for Food, Environmental and Biomedical Analysis)

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15 pages, 4254 KiB

Open AccessArticle

Analysis of the Application of Cryptophane-A\-E in a Mass-Sensing Methane Gas Sensor: Insights from a Numerical Simulation

by Xinlei Liu, Dan Xiao, Qinglan Zhang, Yu Guan, Bin Shen and Jiazhe Li

Chemosensors 2025, 13(5), 179; https://doi.org/10.3390/chemosensors13050179 - 12 May 2025

Viewed by 183

Abstract

Supramolecular compounds are capable of encapsulating small molecules to form host–guest compounds, which can be combined with sound surface wave technology to achieve high-precision detection of specific gases. In this paper, we analyzed the adsorption ability of Cryptophane-A and Cryptophane-E, the caged supramolecular [...] Read more.

Supramolecular compounds are capable of encapsulating small molecules to form host–guest compounds, which can be combined with sound surface wave technology to achieve high-precision detection of specific gases. In this paper, we analyzed the adsorption ability of Cryptophane-A and Cryptophane-E, the caged supramolecular materials, at room temperature by numerical simulation using first principles. The geometrical optimization of Cryptophane-A, Cryptophane-E, and gas molecules was carried out by the Dmol³ module in Materials Studio. Through adsorption calculation of gas molecules, the change of density of states and the magnitude of adsorption energy of Cryptophane-A and E were compared and analyzed. The results show that Cryptophane-A and E are van der Waals adsorption for molecules in gas (except CO₂ and C₂H₆). The adsorption energy of Cryptophane-A is lower than that of Cryptophane-E, but it is more selective and has preferential adsorption for methane. In this paper, we also tried to calculate the adsorption of Cryptophane-A and E on two methane molecules. The result showed that the former could adsorb two methane molecules, but the adsorption energy was lower than that of one methane molecule; the latter could not adsorb two methane molecules stably. The study shows that Cryptophane-A is more suitable as a sensitive material for CH₄ detection, which provides support for the development of acoustic surface wave methane detection technology. Full article

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

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18 pages, 4720 KiB

Open AccessArticle

Detection of 2,4,6-Trichloroanisole in Sparkling Wines Using a Portable E-Nose and Chemometric Tools

by Ramiro Sánchez, Jesús Lozano, Patricia Arroyo and Félix Meléndez

Chemosensors 2025, 13(5), 178; https://doi.org/10.3390/chemosensors13050178 - 11 May 2025

Viewed by 494

Abstract

This study addresses the contamination of sparkling wines by 2,4,6-trichloroanisole (TCA), a compound responsible for the “cork taint” or musty aroma in wines. Currently, its detection requires complex and expensive techniques such as chromatography and sensory panels. An innovative method is proposed using [...] Read more.

This study addresses the contamination of sparkling wines by 2,4,6-trichloroanisole (TCA), a compound responsible for the “cork taint” or musty aroma in wines. Currently, its detection requires complex and expensive techniques such as chromatography and sensory panels. An innovative method is proposed using an electronic nose (e-nose) prototype, offering objective, non-destructive, and cost-effective analysis. The e-nose’s ability to detect TCA at various concentrations was evaluated in sparkling wines from different batches and a spiked wine sample. The results analyzed using Principal Component Analysis (PCA) successfully differentiated the samples. An Artificial Neural Network Discriminant Analysis (ANNDA) classified wines based on whether their TCA concentration exceeded 2 ng/L, achieving 88% accuracy. A quantitative predictive model using Partial Least Squares (PLS) analysis yielded an R² of 0.84 across wines and 0.95 in a single sample. These advances highlight the potential of the e-nose to improve quality control in the wine industry. Full article

(This article belongs to the Special Issue Chemical Sensors for Volatile Organic Compound Detection, 2nd Edition)

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14 pages, 3391 KiB

Open AccessArticle

A UV-Photon-Energy-Integrated Gas Sensor Based on Pt-Nanoparticle-Decorated TiO₂ Nanorods for Room-Temperature Hydrogen Detection

by Ju-Eun Yang, Sohyeon Kim, Jeonghye Yoon, Jeongmin Lee, Il-Kyu Park and Kyoung-Kook Kim

Chemosensors 2025, 13(5), 177; https://doi.org/10.3390/chemosensors13050177 - 11 May 2025

Viewed by 174

Abstract

Hydrogen sensors play a crucial role in ensuring safety in various industrial applications. In this study, we demonstrated the use of a room-temperature hydrogen gas sensor based on Pt-nanoparticle-decorated TiO₂ nanorods (TiO₂ NRs/Pt NP). The TiO₂ NRs were synthesized via [...] Read more.

Hydrogen sensors play a crucial role in ensuring safety in various industrial applications. In this study, we demonstrated the use of a room-temperature hydrogen gas sensor based on Pt-nanoparticle-decorated TiO₂ nanorods (TiO₂ NRs/Pt NP). The TiO₂ NRs were synthesized via a hydrothermal method, followed by Pt deposition using sputtering and thermal annealing. Under UV illumination, the TiO₂ NR/Pt NP gas sensor exhibited a remarkable response of 2.4 at a 1% hydrogen concentration, which is approximately 5.9 times higher than that of bare TiO₂ NRs measured in the dark. This enhancement is attributed to the synergistic effect of Pt NPs, which promote charge separation and spillover for oxygen molecules, and UV activation, which generates additional carriers. Moreover, the sensor demonstrated stable and reliable detection of hydrogen concentrations up to 1% without the need for external heating, underscoring its practical applicability under ambient conditions. These results demonstrate that TiO₂ NRs/Pt NP, combined with UV activation, provide a promising approach for highly sensitive and room-temperature hydrogen detection, offering significant potential for hydrogen monitoring and hydrogen energy systems. Full article

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

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14 pages, 4334 KiB

Open AccessArticle

Study on the Geographic Traceability and Growth Age of Panax ginseng C. A. Meyer Base on an Electronic Nose and Fourier Infrared Spectroscopy

by Jinying Li, Jianlei Qiao, Chang Liu, Zhigang Zhou, Cheng Kong, Zhiyong Chang, Xiaohui Weng and Shujun Zhang

Chemosensors 2025, 13(5), 176; https://doi.org/10.3390/chemosensors13050176 - 10 May 2025

Viewed by 195

Abstract

During ginseng selection, marketing promotion, and sales, it is imperative to expeditiously differentiate the overall quality grades, identify the geographic traces and determine the growth ages. This facilitates the selection of the most appropriate quality grade for each product, thereby ensuring the most [...] Read more.

During ginseng selection, marketing promotion, and sales, it is imperative to expeditiously differentiate the overall quality grades, identify the geographic traces and determine the growth ages. This facilitates the selection of the most appropriate quality grade for each product, thereby ensuring the most efficacious marketing strategy. In this study, a new method is proposed and developed for the classification of ginsengs with diverse geographical traceability and with various growth ages by combining an electronic nose (E-nose) system and machine learning with Fourier-transform infrared spectroscopy (FTIR) as a calibration technology. An investigation has been carried out to discover the differences in the secondary metabolites and odor of three types of ginseng with different geographic traceability and three growth ages of ginseng from the same geographic traceability site. In the proposed method, five types of ginseng samples have been successfully tested. The optimal Mean-SVM model combined with an E-nose system classified ginseng samples with different geographic traceability and different growth years with accuracies of 100% and 82% in the training and test sets, respectively. These results have significant implications for ginseng’s geographic traceability, growth age determination, and overall quality control. It is believed that the future implementation of the proposed method would significantly protect the health and economic interests of consumers as well as promoting the use of an E-nose in the market surveillance of consumable products such as ginseng and other foods. Full article

(This article belongs to the Special Issue Applications of Electronic Nose (E-Nose) and Electronic Tongue (E-Tongue) in Food Quality)

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12 pages, 1201 KiB

Open AccessArticle

Contribution of Gas Chromatography—Mass Spectrometry (GC-MS) to the Volatile Organic Compound Profile of Vespa velutina nigrithorax Larvae

by Omaira de la Hera and Rosa María Alonso

Chemosensors 2025, 13(5), 175; https://doi.org/10.3390/chemosensors13050175 - 10 May 2025

Viewed by 193

Abstract

Vespa velutina is an invasive species introduced by accident into Europe. Since its entry, it has spread rapidly and become a threat to biodiversity and beekeeping. Chemical communication between hornets is one of the main reasons for the proper functioning of hornet colonies. [...] Read more.

Vespa velutina is an invasive species introduced by accident into Europe. Since its entry, it has spread rapidly and become a threat to biodiversity and beekeeping. Chemical communication between hornets is one of the main reasons for the proper functioning of hornet colonies. These signals can be from endogenous and/or exogenous chemical compounds. In this work, the volatile organic compound profile of Vespa velutina larvae was obtained by GC-MS previous solvent extraction procedures. A total of 99 volatile compounds were identified in the larvae volatile profile, of which 33 were common to adult hornets, suggesting a possible endogenous origin and a functional role in physiological processes and chemical communication within the colony. A total of 42 compounds were detected exclusively in the larvae, belonging to aldehydes, alcohols, alkanes, alkenes, amines, ketones, piperidines, pyrrolidines, furanones, fatty acid esters, ethers, and pyridines chemical families. The detection of these compounds in larval stages, before environmental exposure, supports the hypothesis of their endogenous origin. The findings of this work can contribute to widening the knowledge of the biology and chemical composition of V. velutina and could help identify potential semiochemicals useful for the design of more selective and sustainable strategies for its control. Full article

(This article belongs to the Special Issue GC, MS and GC-MS Analytical Methods: Opportunities and Challenges (Third Edition))

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37 pages, 6833 KiB

Open AccessReview

Recent Advances in Aggregation-Induced Emission (AIE) Fluorescent Sensors for Biomolecule Detection

by Kavya S. Keremane, M. Gururaj Acharya, Praveen Naik, Chandi C. Malakar, Kai Wang and Bed Poudel

Chemosensors 2025, 13(5), 174; https://doi.org/10.3390/chemosensors13050174 - 9 May 2025

Viewed by 165

Abstract

Fluorescent sensors are indispensable tools in fields such as molecular biology, clinical diagnostics, biotechnology, and environmental monitoring, due to their high sensitivity, selectivity, biocompatibility, rapid response, and ease of use. However, conventional fluorophores often suffer from aggregation-caused quenching (ACQ), leading to diminished fluorescence [...] Read more.

Fluorescent sensors are indispensable tools in fields such as molecular biology, clinical diagnostics, biotechnology, and environmental monitoring, due to their high sensitivity, selectivity, biocompatibility, rapid response, and ease of use. However, conventional fluorophores often suffer from aggregation-caused quenching (ACQ), leading to diminished fluorescence in the aggregated state. The advent of aggregation-induced emission (AIE) luminogens, which exhibit enhanced fluorescence upon aggregation, offers a powerful solution to this limitation. Their unique photophysical properties have made AIE-based materials highly valuable for diverse applications, including biomedical imaging, optoelectronics, stimuli-responsive systems, drug delivery, and chemical sensing. Notably, AIE-based fluorescent probes are emerging as attractive alternatives to traditional analytical methods owing to their low cost, fast detection, and high selectivity. Over the past two decades, considerable progress has been made in the rational design and development of AIE-active small-molecule fluorescent probes for detecting a wide variety of analytes, such as biologically relevant molecules, drug compounds, volatile organic compounds (VOCs), explosives, and contaminants associated with forensic and food safety analysis. This review highlights recent advances in organic AIE-based fluorescent probes, beginning with the fundamentals of AIE and typical “turn-on” sensing mechanisms, and concluding with a discussion of current challenges and future opportunities in this rapidly evolving research area. Full article

(This article belongs to the Special Issue Advancements and Emerging Applications of Fluorescent Probes for Sensing and Imaging)

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22 pages, 5830 KiB

Open AccessArticle

Analytical Study of the Detection Model for Sulphate Saline Soil Based on Mid-Infrared Spectrometry

by Hanyu Wei, Yong Huang, Sining Li, Jingzhuo Zhao, Wen Liu, Huan Li, Qiushuang Cui and Ruyun Bai

Chemosensors 2025, 13(5), 173; https://doi.org/10.3390/chemosensors13050173 - 8 May 2025

Viewed by 197

Abstract

High soil sulfate levels can inhibit crop growth and accelerate concrete infrastructure degradation, highlighting the critical importance of rapid and accurate sulfate content determination. Nevertheless, conventional analytical techniques are laborious and intricate, and delays in processing may result in alterations to the material, [...] Read more.

High soil sulfate levels can inhibit crop growth and accelerate concrete infrastructure degradation, highlighting the critical importance of rapid and accurate sulfate content determination. Nevertheless, conventional analytical techniques are laborious and intricate, and delays in processing may result in alterations to the material, owing to oxidation. We recognized the accuracy, reproducibility, and non-invasiveness of mid-infrared (MIR) spectroscopy as a rapid and straightforward technique for soil analysis. In this study, soil samples were collected from two depths (0–20 cm and 20–40 cm) across three regions in China: the arid northwestern region, the cold-temperate northeastern zone, and the subtropical southwestern region. One group was mixed with Na₂SO₄ (a readily soluble salt) at mass fractions ranging from 0.1% to 7%, while the other group was mixed with FeS₂ (a sulfide) at mass fractions ranging from 1% to 70%. This study aimed to develop a mid-infrared spectroscopy-based method for analyzing soluble sulfate and sulfide in soil. Three chemometric methods were evaluated: partial least squares regression (PLSR), principal component regression (PCR), and multivariate linear regression (MLR). Results showed that the MLR model provided superior predictive performance. For the 20–40 cm sodium sulfate-mixed soil from the arid northwestern region, the MLR model exhibited the best performance with an Rp² of 0.9535, an RMSEP of 0.0030, an RPD of 4.96, and an RPIQ of 6.26. For the 20–40 cm iron disulfide-mixed soil from the cold-temperate northeastern region, the MLR model demonstrated superior results with Rp², RMSEP, RPD, and RPIQ values of 0.9590, 0.042, 5.97, and 10.94, respectively. For the 0–20 cm iron disulfide-mixed soil from the subtropical southwestern region, the MLR model achieved the best performance with an Rp² of 0.9848, an RMSEP of 0.0025, an RPD of 14.20, and an RPIQ of 25.48. Despite regional variations in soil properties, this study successfully predicted sulfate and sulfide contents in soils from diverse areas using mid-infrared spectroscopy combined with appropriate chemometric methods. This approach provides reliable technical support for soil sulfate detection and offers significant practical value for soil assessment in both agricultural production and engineering construction. Full article

(This article belongs to the Section Optical Chemical Sensors)

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11 pages, 2059 KiB

Open AccessArticle

Low-Cost Electronic Nose for Identification of Wood Species in Which Brazilian Sugar Cane Spirit Was Aged

by Alexandre A. da Silva, Bruna R. Vieira, Elaine Y. Yamauchi, Rosamaria W. C. Li and Jonas Gruber

Chemosensors 2025, 13(5), 172; https://doi.org/10.3390/chemosensors13050172 - 8 May 2025

Viewed by 208

Abstract

Many popular alcoholic beverages, such as Brazilian sugar cane spirit (cachaça), are aged in wood casks to achieve a smoother and more pleasant taste. The type of wood plays an important role in improving the quality of the spirit, with oak being the [...] Read more.

Many popular alcoholic beverages, such as Brazilian sugar cane spirit (cachaça), are aged in wood casks to achieve a smoother and more pleasant taste. The type of wood plays an important role in improving the quality of the spirit, with oak being the most widely used. Due to its elevated price and poor local availability, oak has been gradually replaced in Brazil by other woods, such as Amburana cearensis (Amburana), Cariniana legalis (Jequitibá), Hymenaea courbaril (Jatobá), and Ocotea odorifera (Cinnamon sassafras). For general purposes in beverage quality control and wood identification, and using ethanol/water extracts (cachaça 47% v/v) as a model, this article describes the construction of a low-cost electronic nose that quickly identifies the wood species that was used for aging a cachaça sample. The nose is made of an array of four chemoresistive conductive polymer gas sensors. Principal component and leave-one-out analyses showed perfect classification of all tested samples. Full article

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

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20 pages, 5614 KiB

Open AccessArticle

Heterostructures of CdSe Quantum Dots and g-C₃N₄ Applied as Electrochemiluminescent Probes for the Detection of Hydrogen Peroxide in Human Serum

by Roodney Alberto Carrillo Palomino, Aylén Di Tocco, Gastón Darío Pierini, Gabriela Valeria Porcal and Fernando Javier Arévalo

Chemosensors 2025, 13(5), 171; https://doi.org/10.3390/chemosensors13050171 - 7 May 2025

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Abstract

In this work, we developed a highly sensitive and reproducible electrochemiluminescent sensor based on a heterostructure of cadmium selenide quantum dots capped with 3-mercaptopropionic acid (MPA) + 3-morpholinoethanesulfonic acid (MES) (QDs CdSe) and carbon nitride nanosheets (g-C₃N₄) for the [...] Read more.

In this work, we developed a highly sensitive and reproducible electrochemiluminescent sensor based on a heterostructure of cadmium selenide quantum dots capped with 3-mercaptopropionic acid (MPA) + 3-morpholinoethanesulfonic acid (MES) (QDs CdSe) and carbon nitride nanosheets (g-C₃N₄) for the detection of H₂O₂ in lyophilized serum samples. To enhance the sensor sensitivity, g-C₃N₄ nanosheets were utilized as a platform to immobilize the QDs CdSe. An exhaustive characterization of the heterostructure was conducted, elucidating the interaction mechanism between QDs CdSe and g-C₃N₄. It was revealed that g-C₃N₄ acts as a hole (h⁺) donor, while QDs CdSe act as energy acceptors in a resonance energy transfer process, with the electrochemiluminescence emission originating from the QDs CdSe. The electrochemiluminescence intensity decreases in the presence of H₂O₂ due to the deactivation of the excited states of the QDs CdSe. This electrochemiluminescent sensor demonstrates exceptional performance for detecting H₂O₂ in aqueous systems, achieving a remarkably low limit of detection (LOD) of 1.81 nM, which is more sensitive than most reported sensors to detect H₂O₂. The applicability of the sensor was successfully tested where sub-µM levels of H₂O₂ were accurately quantified. These results highlight the potential of this electrochemiluminescent sensor as a reliable and pre-treatment-free tool for H₂O₂ detection in biochemical studies and human health applications. Full article

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

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13 pages, 2446 KiB

Open AccessArticle

Chlorpyrifos Detection Based on 9-Fluorenone Oxime

by Edoardo Donà and Aleksandra Lobnik

Chemosensors 2025, 13(5), 170; https://doi.org/10.3390/chemosensors13050170 - 6 May 2025

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Abstract

Chlorpyrifos is one of the most toxic organophosphate pesticides, prompting its ban in Europe in 2020. Consequently, developing a detection method that is both selective and sensitive is essential for protecting human health and the environment. In this study, we report for the [...] Read more.

Chlorpyrifos is one of the most toxic organophosphate pesticides, prompting its ban in Europe in 2020. Consequently, developing a detection method that is both selective and sensitive is essential for protecting human health and the environment. In this study, we report for the first time a fluorescent probe based on an oxime for the direct detection of chlorpyrifos. 9-fluorenone oxime, upon deprotonation with a phosphazene base, undergoes a nucleophilic attack on chlorpyrifos, resulting in a significant alteration of its fluorescence properties. Following careful optimization, the method demonstrated excellent linearity (R² = 0.98) over a concentration range of 350 to 6980 μg/L, with a limit of detection of 15.5 μg/L. Furthermore, the probe was successfully applied to chlorpyrifos detection in water samples, yielding satisfactory results. This approach effectively overcomes the stability limitations of enzyme-based fluorescent sensors, offering a robust and innovative solution for the detection of organophosphate pesticides. Full article

(This article belongs to the Section Optical Chemical Sensors)

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16 pages, 5244 KiB

Open AccessArticle

The Sensing Selectivity of Gas Sensors Based on Different Sn-Doped Indium Oxide Films

by Haoran Sheng, Haoyu Li, Yujie Huang, Bochao Zhang, Jiarui Liang, Xinze Zhou, Yuan Tian and Qiang Li

Chemosensors 2025, 13(5), 169; https://doi.org/10.3390/chemosensors13050169 - 5 May 2025

Viewed by 222

Abstract

The gas-sensitive performance and selectivity of gas sensors via different Sn-doped indium oxide (In₂O₃) films have been investigated. The response characteristics were significantly enhanced to methanol (CH₄O), ethanol (C₂H₆O), and acetone (C₃ [...] Read more.

The gas-sensitive performance and selectivity of gas sensors via different Sn-doped indium oxide (In₂O₃) films have been investigated. The response characteristics were significantly enhanced to methanol (CH₄O), ethanol (C₂H₆O), and acetone (C₃H₆O) with the increase in Sn content, while the response time and the recovery time became shorter. The sensor exhibited the strongest response to ethanol, followed by acetone and then methanol with all the ratios of In₂O₃ (90%, 85%, and 80%) and SnO₂ (10%, 15%, and 20%). The mechanism of Sn doping on the gas sensing selectivity was calculated using the density functional theory (DFT) method, which perfectly explained the experimental results. The sensors demonstrated high selectivity towards ethanol, even in the presence of interfering gases. In addition, the sensors showed effective detection of the target gas with 10 ppb and demonstrated good repeatability. This work systematically analyzed the priority selectivity of In₂O₃-based gas sensors, providing a new path for gas detection in multi-interference and complex environments. Full article

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

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15 pages, 3761 KiB

Open AccessArticle

Triply Periodic Minimal Surfaces Mullite Structures for Humidity Detection

by Yurii Milovanov, Arianna Bertero, Bartolomeo Coppola, Paola Palmero and Jean-Marc Tulliani

Chemosensors 2025, 13(5), 168; https://doi.org/10.3390/chemosensors13050168 - 5 May 2025

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Abstract

Three-dimensional-printed complex mullite structures based on triply periodic minimal surfaces (TPMSs, namely, Schwartz and Gyroid) with two different thicknesses (Schwartz 1 and Gyroid 1–4 mm, Schwartz 2 and Gyroid 2–6 mm) were fabricated and tested as humidity sensors. The samples were sintered at [...] Read more.

Three-dimensional-printed complex mullite structures based on triply periodic minimal surfaces (TPMSs, namely, Schwartz and Gyroid) with two different thicknesses (Schwartz 1 and Gyroid 1–4 mm, Schwartz 2 and Gyroid 2–6 mm) were fabricated and tested as humidity sensors. The samples were sintered at 1450 °C and tested in the range from 0% to 89% relative humidity (RH) at room temperature to evaluate the effect of geometry and thickness on humidity sensitivity. After water vapor exposure at room temperature, the response was 2.84 under 89 RH% for the Schwartz 1 structure (1.36 for the Schwartz 2 structure) and 1.21 for the Gyroid 1 structure (7.00 for the Gyroid 2 structure). The results showed that, at 89% RH, the best response of the sensors was achieved for the Gyroid 2 structure. Sensors exhibit good repeatability, and there was no interference in the presence of other gases. Full article

(This article belongs to the Special Issue Sensors for Food Testing, Environmental Analysis, and Medical Diagnostics)

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15 pages, 4930 KiB

Open AccessArticle

Organophosphorus Pesticide Photoelectrochemical/Electrochemical Dual-Mode Smartsensors Derived from Synergistic Co,N-TiO₂@ZrO₂/3DGH Platform

by Zhouxiaolong Zhang, Hongting Ma, Hao Mo and Nan Zhu

Chemosensors 2025, 13(5), 167; https://doi.org/10.3390/chemosensors13050167 - 5 May 2025

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Abstract

Organophosphorus pesticides (OPs), while pivotal for agricultural productivity, pose severe environmental and health risks due to their persistence and bioaccumulation. Existing detection methods, such as chromatography and spectroscopy, face limitations in field adaptability, cost, and operational complexity. To address these challenges, this study [...] Read more.

Organophosphorus pesticides (OPs), while pivotal for agricultural productivity, pose severe environmental and health risks due to their persistence and bioaccumulation. Existing detection methods, such as chromatography and spectroscopy, face limitations in field adaptability, cost, and operational complexity. To address these challenges, this study introduces a novel dual-mode photoelectrochemical–electrochemical (PEC-EC) sensor based on a Co,N-TiO₂@ZrO₂/3DGH nanocomposite. The sensor synergistically integrates zirconium oxide (ZrO₂) for selective OP capture via phosphate-Zr coordination, cobalt-nitrogen co-doped titanium dioxide (Co,N-TiO₂) for visible-light responsiveness, and a three-dimensional graphene hydrogel (3DGH) for enhanced conductivity. In the PEC mode under light irradiation, OP adsorption induces charge recombination, yielding a logarithmic photocurrent attenuation with a detection limit of 0.058 ng mL⁻¹. Subsequently, the EC mode via square wave voltammetry (SWV) self-validates the results, achieving a detection limit of 0.716 ng mL⁻¹. The dual-mode system demonstrates exceptional reproducibility, long-term stability, and selectivity against common interferents. Parallel measurements revealed <5% inter-mode discrepancy, validating the intrinsic self-checking capability. This portable platform bridges the gap between laboratory-grade accuracy and field-deployable simplicity, offering transformative potential for environmental monitoring and food safety management. Full article

(This article belongs to the Special Issue Recent Advances in Chemical Sensors in Dalian University of Technology: Fundamental Science and Applications)

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13 pages, 1606 KiB

Open AccessArticle

Discovery of Lithospermate B as a Potential Ligand for the Malarial E2 Ubiquitin-Conjugating Enzyme via Multiplexed Native Mass Spectrometry

by Jianying Han, Wesley C. Van Voorhis, Ronald J. Quinn and Miaomiao Liu

Chemosensors 2025, 13(5), 166; https://doi.org/10.3390/chemosensors13050166 - 5 May 2025

Viewed by 196

Abstract

There is an urgent need for novel therapeutics to combat Plasmodium falciparum, especially in light of increasing drug resistance. Here, we present a multiplexed native mass spectrometry (MS) platform capable of simultaneously screening multiple protein targets against chemically diverse crude extracts with [...] Read more.

There is an urgent need for novel therapeutics to combat Plasmodium falciparum, especially in light of increasing drug resistance. Here, we present a multiplexed native mass spectrometry (MS) platform capable of simultaneously screening multiple protein targets against chemically diverse crude extracts with minimal sample preparation. A mixture of seven malarial proteins was analyzed under optimized native MS conditions, enabling the detection of specific ligand binding events. Using this platform, lithospermate B from Salvia miltiorrhiza (Danshen) was identified as a novel ligand for a malarial ubiquitin-conjugating enzyme with moderate affinity (Kd = 30.5 ± 2.5 μM). This is the first report linking lithospermate B to a malarial protein target, highlighting the potential of native MS to uncover new bioactivities of known natural products. This approach significantly enhances the throughput of protein–ligand screening and offers a powerful tool for early-stage natural product-based drug discovery. Full article

(This article belongs to the Special Issue GC, MS and GC-MS Analytical Methods: Opportunities and Challenges (Third Edition))

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16 pages, 5088 KiB

Open AccessArticle

A Minimal Electronic Nose Based on Graphene Functionalized with Metalated Pyrazinoporphyrazines and Phthalocyanines for Ammonia, Benzene, and Hydrogen Sulfide Discrimination

by Sonia Freddi, Luca Vaghi, Andrea Penoni, Luca Scapinello and Luigi Sangaletti

Chemosensors 2025, 13(5), 165; https://doi.org/10.3390/chemosensors13050165 - 5 May 2025

Viewed by 262

Abstract

The development of electronic noses is, nowadays, essential for several applications, including breath analysis and industrial security. Ammonia, benzene, and hydrogen sulfide are particularly important due to their environmental and health impacts. Here, graphene-based sensors, functionalized with unconventional in-house synthesized zinc and copper [...] Read more.

The development of electronic noses is, nowadays, essential for several applications, including breath analysis and industrial security. Ammonia, benzene, and hydrogen sulfide are particularly important due to their environmental and health impacts. Here, graphene-based sensors, functionalized with unconventional in-house synthesized zinc and copper octyl-pyrazinoporphyrazines and commercially available zinc phthalocyanine, have been prepared. Enhanced solubility given by the octyl chains allowed us to exploit drop-casting as a straightforward functionalization technique. The sensors demonstrated excellent performance for detecting ammonia, benzene, and hydrogen sulfide as a single sensor, with a competitive detection limit and a high sensitivity compared to the state of the art. In particular, functionalization enabled the detection of hydrogen sulfide, for which no response is observed with bare graphene, and lowered the detection limit for all the gases compared to bare graphene. Additionally, the prepared sensors have been assembled into an e-nose that shows promising potentiality to be used for both industrial and medical applications thanks to its excellent discrimination capability of single gases and mixtures. Full article

(This article belongs to the Special Issue Advanced Chemical Sensors for Gas Detection)

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13 pages, 2800 KiB

Open AccessArticle

Using BiOI/BiOCl Composite-Enhanced Cathodic Photocurrent and Amplifying Signal Variation in AgI for Developing a Highly Sensitive Photoelectrochemical Immunosensing Platform

by Mengyang Zhang, Weikang Wan, Shurui Wang, Huiyu Zeng, Yang Wu, Zhihui Dai and Wenwen Tu

Chemosensors 2025, 13(5), 164; https://doi.org/10.3390/chemosensors13050164 - 5 May 2025

Viewed by 178

Abstract

Photoelectrochemical (PEC) sensors have emerged as potential analysis techniques in recent years due to PEC’s benefits, which include straightforward operation, quick response times, and basic equipment. In this work, a new PEC sandwich immunoassay was fabricated, which was based on low-toxicity BiOI/BiOCl composites [...] Read more.

Photoelectrochemical (PEC) sensors have emerged as potential analysis techniques in recent years due to PEC’s benefits, which include straightforward operation, quick response times, and basic equipment. In this work, a new PEC sandwich immunoassay was fabricated, which was based on low-toxicity BiOI/BiOCl composites accompanied by enhanced signal detection via AgI-conjugated antibodies (Ab₂-AgI). Specifically, the low-toxicity inorganic semiconductor BiOI/BiOCl composites were first utilized in PEC bioanalysis. Owing to the unique configuration of energy levels between BiOI and BiOCl, the photoelectric response was more excellent than those of BiOI or BiOCl alone. Moreover, the Ab₂-AgI conjugates were utilized as signal amplification components through the specific antibody–antigen immunoreaction. In the presence of target Ag, the immobilized Ab₂-AgI conjugates clearly improve the steric hindrance of the sensing electrode and effectively hinder the transfer of photo-induced holes; meanwhile, AgI NPs can competitively absorb excitation light. A new PEC immunosensing platform for detecting tumor markers at 0 V under visible light excitation was developed, and using carcinoembryonic antigen (CEA) as a model analyte demonstrated an ultra-low detection limit of 4.9 fg·mL⁻¹. Meanwhile, it demonstrated excellent specificity and stability, potentially opening up a novel and promising platform for detecting other critical biomarkers. Full article

(This article belongs to the Special Issue Electrochemical Biosensors: Advances and Prospects)

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48 pages, 7068 KiB

Open AccessReview

Colorimetric Molecularly Imprinted Polymer-Based Sensors for Rapid Detection of Organic Compounds: A Review

by Juan Carlos Bravo-Yagüe, Gema Paniagua-González, Rosa María Garcinuño, Asunción García-Mayor and Pilar Fernández-Hernando

Chemosensors 2025, 13(5), 163; https://doi.org/10.3390/chemosensors13050163 - 4 May 2025

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Abstract

This review offers a comprehensive examination of the development and current state of the art in the field of molecularly imprinted polymer (MIP)-based colorimetric sensors, focusing on their potential for the rapid detection of organic compounds. These MIP-sensors are gaining considerable attention due [...] Read more.

This review offers a comprehensive examination of the development and current state of the art in the field of molecularly imprinted polymer (MIP)-based colorimetric sensors, focusing on their potential for the rapid detection of organic compounds. These MIP-sensors are gaining considerable attention due to their distinctive capacity to modify sensor surfaces by creating recognition cavities within the polymer matrix, providing a versatile and highly selective platform for detecting a broad spectrum of analytes. This review systematically examines different types of MIP-based colorimetric sensors, attending to the target analyte, highlighting their applications in on-site sample detection, drug monitoring, environmental analysis, and food safety detection. The integration of novel technologies, such as nanozymes and smartphone-based detection, which enhance the capabilities of colorimetric MIP sensors, is also addressed. The sensors are particularly valuable due to their low cost, rapid response times, portability, and ease of use. Finally, the review outlines the future challenges for the development of MIP-based colorimetric sensors, focusing on overcoming existing limitations, improving sensor performance, and expanding their applications across various fields. Full article

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

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21 pages, 5044 KiB

Open AccessArticle

¹H-NMR Spectroscopy and Chemometric Fingerprinting for the Authentication of Organic Extra Virgin Olive Oils

by Silvana M. Azcarate, Maria P. Segura-Borrego, Rocío Ríos-Reina and Raquel M. Callejón

Chemosensors 2025, 13(5), 162; https://doi.org/10.3390/chemosensors13050162 - 1 May 2025

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Abstract

The authentication of organic extra virgin olive oils (OEVOOs) is crucial for quality control and fraud prevention. This study applies proton-nuclear magnetic resonance (¹H-NMR) spectroscopy combined with chemometric analysis as a non-destructive, untargeted approach to differentiate EVOOs based on cultivation method [...] Read more.

The authentication of organic extra virgin olive oils (OEVOOs) is crucial for quality control and fraud prevention. This study applies proton-nuclear magnetic resonance (¹H-NMR) spectroscopy combined with chemometric analysis as a non-destructive, untargeted approach to differentiate EVOOs based on cultivation method (organic vs. conventional) and variety (Hojiblanca vs. Picual). Principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) demonstrated well-defined sample differentiation, while the variable importance in projection (VIP) selection and Tukey’s test identified key spectral regions responsible for classification. The results showed that sterols and lipid-related compounds played a major role in distinguishing organic from conventional oils, whereas fatty acids and phenolic compounds were more relevant for cultivar differentiation. These findings align with known metabolic differences, where Picual oils generally exhibit higher polyphenol content, and a distinct fatty acid composition compared to Hojiblanca. The agreement between chemometric classification models and statistical tests supports the potential of ¹H-NMR for OEVOO authentication. This method provides a comprehensive and reproducible metabolic fingerprint, enabling differentiation based on both agronomic practices and genetic factors. These findings suggest that ¹H-NMR spectroscopy, coupled with multivariate analysis, could be a valuable tool for quality control and fraud detection in the olive oil industry. Full article

(This article belongs to the Special Issue Chemometrics for Food, Environmental and Biological Analysis)

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23 pages, 3229 KiB

Open AccessReview

A Systematic Review of the Applications of Electronic Nose and Electronic Tongue in Food Quality Assessment and Safety

by Ramkumar Vanaraj, Bincy I.P, Gopiraman Mayakrishnan, Ick Soo Kim and Seong-Cheol Kim

Chemosensors 2025, 13(5), 161; https://doi.org/10.3390/chemosensors13050161 - 1 May 2025

Viewed by 674

Abstract

Food quality assessment is a critical aspect of food production and safety, ensuring that products meet both regulatory and consumer standards. Traditional methods such as sensory evaluation, chromatography, and spectrophotometry are widely used but often suffer from limitations, including subjectivity, high costs, and [...] Read more.

Food quality assessment is a critical aspect of food production and safety, ensuring that products meet both regulatory and consumer standards. Traditional methods such as sensory evaluation, chromatography, and spectrophotometry are widely used but often suffer from limitations, including subjectivity, high costs, and time-consuming procedures. In recent years, the development of electronic nose (e-nose) and electronic tongue (e-tongue) technologies has provided rapid, objective, and reliable alternatives for food quality monitoring. These bio-inspired sensing systems mimic human olfactory and gustatory functions through sensor arrays and advanced data processing techniques, including artificial intelligence and pattern recognition algorithms. The e-nose is primarily used for detecting volatile organic compounds (VOCs) in food, making it effective for freshness evaluation, spoilage detection, aroma profiling, and adulteration identification. Meanwhile, the e-tongue analyzes liquid-phase components and is widely applied in taste assessment, beverage authentication, fermentation monitoring, and contaminant detection. Both technologies are extensively used in the quality control of dairy products, meat, seafood, fruits, beverages, and processed foods. Their ability to provide real-time, non-destructive, and high-throughput analysis makes them valuable tools in the food industry. This review explores the principles, advantages, and applications of e-nose and e-tongue systems in food quality assessment. Additionally, it discusses emerging trends, including IoT-based smart sensing, advances in nanotechnology, and AI-driven data analysis, which are expected to further enhance their efficiency and accuracy. With continuous innovation, these technologies are poised to revolutionize food safety and quality control, ensuring consumer satisfaction and compliance with global standards. Full article

(This article belongs to the Special Issue Applications of Electronic Nose (E-Nose) and Electronic Tongue (E-Tongue) in Food Quality)

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19 pages, 1900 KiB

Open AccessReview

Electrodes for pH Sensing Based on Stainless Steel: Mechanism, Surface Modification, Potentiometric Performance, and Prospects

by Javier E. Vilasó-Cadre, Juan Hidalgo, María A. Arada-Pérez, Iván A. Reyes-Domínguez, Graziella L. Turdean, Roel Cruz, Juan J. Piña Leyte-Vidal, Lázaro A. González-Fernández, Manuel Sánchez-Polo and Luis Hidalgo

Chemosensors 2025, 13(5), 160; https://doi.org/10.3390/chemosensors13050160 - 1 May 2025

Viewed by 225

Abstract

The fabrication of miniaturized and durable pH electrodes is a key requirement for developing advanced analytical devices for both industrial and biomedical applications. Glass electrodes are not an option in these cases. Electrodes based on metal oxides have been the most studied for [...] Read more.

The fabrication of miniaturized and durable pH electrodes is a key requirement for developing advanced analytical devices for both industrial and biomedical applications. Glass electrodes are not an option in these cases. Electrodes based on metal oxides have been the most studied for pH sensing in these and other applications. Stainless steel pH electrodes have been an option for many years, both for measurement using steel as a sensitive material and using it as a substrate for the deposition of other metal oxides; in the latter case, the sensitive ability of stainless steel seems to play a crucial role. In addition, recent use as a substrate for materials such as polymers, carbon nanotubes, and metallic nanoparticles should be considered. This paper presents a review of this type of pH electrode, covering aspects related to the sensing mechanism, the treatment of stainless steel, potentiometric performances, applications, and the prospects of these sensors for use in modern analytical instruments. Sensing with the oxide passive layer and the artificial layer by oxidation treatments is analyzed. The use of metal oxides and other materials as the sensitive layer on stainless steel, their application in wearable devices, microneedle sensors, and combination with field-effect transistors for high-temperature pH sensing are covered as the most current and promising applications. Full article

(This article belongs to the Special Issue Advanced Nanomaterials-Based (Bio)sensors for Electrochemical Detection and Analysis)

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22 pages, 2532 KiB

Open AccessReview

A Review on Xanthine Oxidase-Based Electrochemical Biosensors: Food Safety and Quality Control Applications

by Totka Dodevska

Chemosensors 2025, 13(5), 159; https://doi.org/10.3390/chemosensors13050159 - 1 May 2025

Viewed by 310

Abstract

Electrochemical biosensors are integrated bio-receptor–transducer devices that convert specific biological interactions into measurable electrical signals. Over the past decade, the use of novel nanomaterials, advanced enzyme immobilization techniques, and enhanced sensor architectures have been extensively studied, yielding significant progress in the design of [...] Read more.

Electrochemical biosensors are integrated bio-receptor–transducer devices that convert specific biological interactions into measurable electrical signals. Over the past decade, the use of novel nanomaterials, advanced enzyme immobilization techniques, and enhanced sensor architectures have been extensively studied, yielding significant progress in the design of highly sensitive, rapid, and reliable electrochemical biosensors. In the modern food industry various types of electrochemical biosensors are used, playing essential roles in the processes monitoring and optimization. This review highlights the strategies implemented to improve the analytical performance of electrochemical enzyme biosensors based on xanthine oxidase (XOx) for the quantitative detection of xanthine (X) and hypoxanthine (Hx), analytes relevant to the field of food quality control. The article covers recent developments (mainly original studies reported from 2010 to date) in the substrate materials, different electrode designs, working principles, advantages, limitations, and applications of XOx biosensors for meat freshness assessment. The article is meant to be a valuable resource that provides insights for improving design for the next generation bio-electroanalytical platforms to ensure food safety. Full article

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

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