Pub Date : 2024-05-24DOI: 10.3390/chemosensors12060087
Maria Helena Gonçalves, M. Braunger, A. de Barros, R. C. Hensel, Julianna G. Dalafini, I. Mazali, Leonardo M. Corrêa, Daniel Ugarte, A. Riul, Varlei Rodrigues
Silver nanoparticles (AgNPs) possess unique characteristics ideal for enhancing device sensitivity, primarily due to their high surface-to-volume ratio facilitating heightened interaction with analytes. Integrating AgNPs into polymers or carbon-based materials results in nanocomposites with synergistic properties, enabling the detection of minute changes in the environment across various applications. In this study, we investigate the adsorption kinetics of AgNPs within multilayered layer-by-layer (LbL) structures, specifically examining the impact of AgNPs concentration in the LbL film formation that is further explored as sensing units in an impedimetric microfluidic e-tongue. Although absorption kinetic studies are infrequent, they are crucial to optimize the AgNPs adsorption and distribution within LbL structures, significantly influencing upcoming applications. Through systematic variation of AgNPs concentration within identical LbL architectures, we applied the films as sensing units in a microfluidic e-tongue capable of distinguishing food enhancers sharing the umami taste profile. Across all tested scenarios, our approach consistently achieves robust sample separation, evidenced by silhouette coefficient, principal component analyses, and long-term stability. This work contributes to exploring controlled nanomaterial-based developments, emphasizing the importance of precise parameter control for enhanced sensor performance across diverse analytical applications.
{"title":"Controlled Insertion of Silver Nanoparticles in LbL Nanostructures: Fine-Tuning the Sensing Units of an Impedimetric E-Tongue","authors":"Maria Helena Gonçalves, M. Braunger, A. de Barros, R. C. Hensel, Julianna G. Dalafini, I. Mazali, Leonardo M. Corrêa, Daniel Ugarte, A. Riul, Varlei Rodrigues","doi":"10.3390/chemosensors12060087","DOIUrl":"https://doi.org/10.3390/chemosensors12060087","url":null,"abstract":"Silver nanoparticles (AgNPs) possess unique characteristics ideal for enhancing device sensitivity, primarily due to their high surface-to-volume ratio facilitating heightened interaction with analytes. Integrating AgNPs into polymers or carbon-based materials results in nanocomposites with synergistic properties, enabling the detection of minute changes in the environment across various applications. In this study, we investigate the adsorption kinetics of AgNPs within multilayered layer-by-layer (LbL) structures, specifically examining the impact of AgNPs concentration in the LbL film formation that is further explored as sensing units in an impedimetric microfluidic e-tongue. Although absorption kinetic studies are infrequent, they are crucial to optimize the AgNPs adsorption and distribution within LbL structures, significantly influencing upcoming applications. Through systematic variation of AgNPs concentration within identical LbL architectures, we applied the films as sensing units in a microfluidic e-tongue capable of distinguishing food enhancers sharing the umami taste profile. Across all tested scenarios, our approach consistently achieves robust sample separation, evidenced by silhouette coefficient, principal component analyses, and long-term stability. This work contributes to exploring controlled nanomaterial-based developments, emphasizing the importance of precise parameter control for enhanced sensor performance across diverse analytical applications.","PeriodicalId":10057,"journal":{"name":"Chemosensors","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141101041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-24DOI: 10.3390/chemosensors12060088
Peng Wang, Jinyan Li, Lingling Guo, Jiaxun Li, Feng He, Haitao Zhang, Hai Chi
Food safety inspections are an essential aspect of food safety monitoring. Rapid, accurate, and low-cost food analysis can considerably increase the efficiency of food safety inspections. The lateral flow immunochromatographic assay (LFIA) technique has recently grown in popularity due to its ease of use and high efficiency. It is currently commonly utilized in food inspection. In this review, we briefly introduce the principle and classification of LFIA, critically discuss the recent application status of LFIA in food contaminantion detection, and finally propose that artificial intelligence and information technology will further advance the development of LFIA in the field of food safety monitoring.
{"title":"The Developments on Lateral Flow Immunochromatographic Assay for Food Safety in Recent 10 Years: A Review","authors":"Peng Wang, Jinyan Li, Lingling Guo, Jiaxun Li, Feng He, Haitao Zhang, Hai Chi","doi":"10.3390/chemosensors12060088","DOIUrl":"https://doi.org/10.3390/chemosensors12060088","url":null,"abstract":"Food safety inspections are an essential aspect of food safety monitoring. Rapid, accurate, and low-cost food analysis can considerably increase the efficiency of food safety inspections. The lateral flow immunochromatographic assay (LFIA) technique has recently grown in popularity due to its ease of use and high efficiency. It is currently commonly utilized in food inspection. In this review, we briefly introduce the principle and classification of LFIA, critically discuss the recent application status of LFIA in food contaminantion detection, and finally propose that artificial intelligence and information technology will further advance the development of LFIA in the field of food safety monitoring.","PeriodicalId":10057,"journal":{"name":"Chemosensors","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141101468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-22DOI: 10.3390/chemosensors12060086
Renato L. Gil, L. Rodríguez-Lorenzo, Begoña Espiña, Raquel B. Queirós
Graphene oxide (GO) was used as an ion-to-electron transducer for all-solid-state nitrate electrodes based on an alkyl ammonium salt as the sensing element. Commercially available carbon screen-printed electrodes modified with GO were used as conductive substrates, whose morphology and distribution along the surface were evaluated by scanning electron microscopy and Raman spectroscopy. The potentiometric performance of the GO-based electrodes revealed a Nernstian slope of −53.5 ± 2.0 mV decade−1 (R2 = 0.9976 ± 0.0015) in the range from 3.0 × 10−6 to 10−2 M and a lower limit of detection of 1.9 × 10−6 M. An impressive reproducibility between equally prepared electrodes (n = 15) was demonstrated by a variation of <6% for the calibration parameters. Constant current chronopotentiometry and water layer tests were used to evaluate the potential signal stability, providing similar performance to previously published works with graphene-based ion-selective electrodes. Notably, the GO-based sensors showed the absence of a water layer, a long-term drift of 0.3 mV h−1, and a stable performance (LOD and sensitivity) over 3 months. The applicability of the proposed sensors was demonstrated in determining nitrate levels in water samples with great accuracy, yielding recovery values from 87.8 to 107.9%, and comparable (p > 0.05) results to a commercial nitrate probe. These findings demonstrate the use of GO as an alternative ion-to-electron transducer for the fabrication of all-solid-state potentiometric electrodes.
在以烷基铵盐为传感元件的全固态硝酸盐电极中，氧化石墨烯（GO）被用作离子到电子的换能器。使用市售的经 GO 修饰的碳丝网印刷电极作为导电基底，并通过扫描电子显微镜和拉曼光谱对其形态和沿表面的分布进行了评估。基于 GO 的电极的电位性能显示，在 3.0 × 10-6 至 10-2 M 的范围内，其 Nernstian 斜率为 -53.5 ± 2.0 mV decade-1（R2 = 0.9976 ± 0.0015），检测下限为 1.9 × 10-6 M。这些研究结果表明，在制造全固态电位电极时，可以使用 GO 作为离子到电子的替代换能器。
{"title":"All-Solid-State Potentiometric Sensor Based on Graphene Oxide as Ion-to-Electron Transducer for Nitrate Detection in Water Samples","authors":"Renato L. Gil, L. Rodríguez-Lorenzo, Begoña Espiña, Raquel B. Queirós","doi":"10.3390/chemosensors12060086","DOIUrl":"https://doi.org/10.3390/chemosensors12060086","url":null,"abstract":"Graphene oxide (GO) was used as an ion-to-electron transducer for all-solid-state nitrate electrodes based on an alkyl ammonium salt as the sensing element. Commercially available carbon screen-printed electrodes modified with GO were used as conductive substrates, whose morphology and distribution along the surface were evaluated by scanning electron microscopy and Raman spectroscopy. The potentiometric performance of the GO-based electrodes revealed a Nernstian slope of −53.5 ± 2.0 mV decade−1 (R2 = 0.9976 ± 0.0015) in the range from 3.0 × 10−6 to 10−2 M and a lower limit of detection of 1.9 × 10−6 M. An impressive reproducibility between equally prepared electrodes (n = 15) was demonstrated by a variation of <6% for the calibration parameters. Constant current chronopotentiometry and water layer tests were used to evaluate the potential signal stability, providing similar performance to previously published works with graphene-based ion-selective electrodes. Notably, the GO-based sensors showed the absence of a water layer, a long-term drift of 0.3 mV h−1, and a stable performance (LOD and sensitivity) over 3 months. The applicability of the proposed sensors was demonstrated in determining nitrate levels in water samples with great accuracy, yielding recovery values from 87.8 to 107.9%, and comparable (p > 0.05) results to a commercial nitrate probe. These findings demonstrate the use of GO as an alternative ion-to-electron transducer for the fabrication of all-solid-state potentiometric electrodes.","PeriodicalId":10057,"journal":{"name":"Chemosensors","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141113104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-21DOI: 10.3390/chemosensors12060085
Xiaqing Fu, Zirui Qiao, Hangyu Zhou, Dan Xie
Since the discovery of innovative two-dimensional (2D) materials, significant efforts have been dedicated to exploring their intriguing properties and emerging applications. Among all candidates, transition metal dichalcogenides (TMDs) have proven to be exceptional for gas sensing, while defects engineering has been introduced to modify the pristine TMDs for better gas sensing performances. In this review, we systematically summarize types of defects, advanced characterization techniques, and state-of-the-art controllable synthetic methods. Various types of defects in TMDs can induce diverse changes in chemical and electron structures, which are closely correlated with gas sensing ability. Therefore, connections between defects and gas sensing mechanisms and performances have been addressed based on both defect categories and electron affinity of gases. This review will be a guide for researchers in defective materials and open up the field of precisely synthesis chemistry and deepen the understanding of the underlying effects of defects in other 2D materials.
{"title":"Defect Engineering in Transition Metal Dichalcogenide-Based Gas Sensors","authors":"Xiaqing Fu, Zirui Qiao, Hangyu Zhou, Dan Xie","doi":"10.3390/chemosensors12060085","DOIUrl":"https://doi.org/10.3390/chemosensors12060085","url":null,"abstract":"Since the discovery of innovative two-dimensional (2D) materials, significant efforts have been dedicated to exploring their intriguing properties and emerging applications. Among all candidates, transition metal dichalcogenides (TMDs) have proven to be exceptional for gas sensing, while defects engineering has been introduced to modify the pristine TMDs for better gas sensing performances. In this review, we systematically summarize types of defects, advanced characterization techniques, and state-of-the-art controllable synthetic methods. Various types of defects in TMDs can induce diverse changes in chemical and electron structures, which are closely correlated with gas sensing ability. Therefore, connections between defects and gas sensing mechanisms and performances have been addressed based on both defect categories and electron affinity of gases. This review will be a guide for researchers in defective materials and open up the field of precisely synthesis chemistry and deepen the understanding of the underlying effects of defects in other 2D materials.","PeriodicalId":10057,"journal":{"name":"Chemosensors","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141113805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-16DOI: 10.3390/chemosensors12050083
Fazia Mechai, Ahmad Al Shboul, Mohand Outahar Bensidhoum, Hossein Anabestani, Mohsen Ketabi, Ricardo Izquierdo
This research contributes to work on synthesizing zinc oxide nanoparticles (ZnO NPs) at room temperature (RT) and their utilization in flexible gas sensors. RT ZnO NP synthesis with a basicity solution (pH ≈ 13) demonstrates an efficient method for synthesizing well-crystalline ZnO NPs (RT.pH13) comparable to those synthesized by the hydrothermal method (hyd.C). The RT.pH13 achieved a high thermal stability with minimal organic reside impurities (~4.2 wt%), 30–80 nm particle size distribution, and a specific surface area (14 m2 g−1). The synthesized pre- and post-calcinated RT.pH13 NPs were then incorporated into flexible sensors for gas sensing applications at ambient conditions (RT and relative humidity of 30–50%). The pre-calcinated ZnO-based sensor (RT.pH13) demonstrated superior sensitivity to styrene and acetic acid and lower sensitivity to dimethyl-6-octenal. The calcinated ZnO-based sensor (RT.pH13.C) exhibited lower sensitivity to styrene and acetic acid, but heightened sensitivity to benzene, acetone, and ethanol. This suggests a correlation between sensitivity and structural transformations following calcination. The investigation of the sensing mechanisms highlighted the role of surface properties in the sensors’ affinity for specific gas molecules and temperature and humidity variations. The study further explored the sensors’ mechanical flexibility, which is crucial for flexible Internet of Things (IoT) applications.
{"title":"Influence of pH on Room-Temperature Synthesis of Zinc Oxide Nanoparticles for Flexible Gas Sensor Applications","authors":"Fazia Mechai, Ahmad Al Shboul, Mohand Outahar Bensidhoum, Hossein Anabestani, Mohsen Ketabi, Ricardo Izquierdo","doi":"10.3390/chemosensors12050083","DOIUrl":"https://doi.org/10.3390/chemosensors12050083","url":null,"abstract":"This research contributes to work on synthesizing zinc oxide nanoparticles (ZnO NPs) at room temperature (RT) and their utilization in flexible gas sensors. RT ZnO NP synthesis with a basicity solution (pH ≈ 13) demonstrates an efficient method for synthesizing well-crystalline ZnO NPs (RT.pH13) comparable to those synthesized by the hydrothermal method (hyd.C). The RT.pH13 achieved a high thermal stability with minimal organic reside impurities (~4.2 wt%), 30–80 nm particle size distribution, and a specific surface area (14 m2 g−1). The synthesized pre- and post-calcinated RT.pH13 NPs were then incorporated into flexible sensors for gas sensing applications at ambient conditions (RT and relative humidity of 30–50%). The pre-calcinated ZnO-based sensor (RT.pH13) demonstrated superior sensitivity to styrene and acetic acid and lower sensitivity to dimethyl-6-octenal. The calcinated ZnO-based sensor (RT.pH13.C) exhibited lower sensitivity to styrene and acetic acid, but heightened sensitivity to benzene, acetone, and ethanol. This suggests a correlation between sensitivity and structural transformations following calcination. The investigation of the sensing mechanisms highlighted the role of surface properties in the sensors’ affinity for specific gas molecules and temperature and humidity variations. The study further explored the sensors’ mechanical flexibility, which is crucial for flexible Internet of Things (IoT) applications.","PeriodicalId":10057,"journal":{"name":"Chemosensors","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140969883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Surface-enhanced Raman scattering (SERS) provides an alternative rapid detection method for pesticide residues in food, but fenvalerate possesses poor affinity to the novel metal substrate, thus restricting its analysis. To break this bottleneck, a SERS-active platform with an Ag/rGO composite structure was engineered using a facile method for fenvalerate detection. Ag nanoparticles with a 60 nm diameter can grow evenly on the top and bottom of rGO layers under intense ultrasonic oscillation, and rGO in hybrid material acts as an ideal hotspot holder between the gaps of Ag nanoparticles, not only allowing the interaction area to be enhanced both electromagnetically and chemically but also enabling the capture and enrichment of fenvalerate pesticide molecules into the “hotspot” area to improve detection sensitivity. Ag/rGO composite substrate possesses superior SERS performance with an ultralow detectable concentration of 4-aminothiophenol (10−10 M) and good reproducibility, endowing the material with a better enhancement effect than pure Ag nanoparticles. When used as the SERS substrate for fenvalerate detection, Ag/rGO composite material showed excellent performance in both experiments and theoretical calculation, with the limit of detection (LOD) of fenvalerate being as low as 1.69 × 10−5 mg/kg and a detection model with an R2 of 99.2%, demonstrating its exciting potential as a SERS substrate for pesticides detection.
{"title":"Synergistic Enhancement Effect of Ag/rGO as SERS Platform for Capture and Trace Detection of Fenvalerate Molecules","authors":"Minghui Yu, Chongyang Qin, Zhi Yu, Biao Sun, Dejiang Ni, De Zhang, Pei-Fen Liang","doi":"10.3390/chemosensors12050082","DOIUrl":"https://doi.org/10.3390/chemosensors12050082","url":null,"abstract":"Surface-enhanced Raman scattering (SERS) provides an alternative rapid detection method for pesticide residues in food, but fenvalerate possesses poor affinity to the novel metal substrate, thus restricting its analysis. To break this bottleneck, a SERS-active platform with an Ag/rGO composite structure was engineered using a facile method for fenvalerate detection. Ag nanoparticles with a 60 nm diameter can grow evenly on the top and bottom of rGO layers under intense ultrasonic oscillation, and rGO in hybrid material acts as an ideal hotspot holder between the gaps of Ag nanoparticles, not only allowing the interaction area to be enhanced both electromagnetically and chemically but also enabling the capture and enrichment of fenvalerate pesticide molecules into the “hotspot” area to improve detection sensitivity. Ag/rGO composite substrate possesses superior SERS performance with an ultralow detectable concentration of 4-aminothiophenol (10−10 M) and good reproducibility, endowing the material with a better enhancement effect than pure Ag nanoparticles. When used as the SERS substrate for fenvalerate detection, Ag/rGO composite material showed excellent performance in both experiments and theoretical calculation, with the limit of detection (LOD) of fenvalerate being as low as 1.69 × 10−5 mg/kg and a detection model with an R2 of 99.2%, demonstrating its exciting potential as a SERS substrate for pesticides detection.","PeriodicalId":10057,"journal":{"name":"Chemosensors","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140971037","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-16DOI: 10.3390/chemosensors12050084
Prashant K. Kasare, Sea-Fue Wang
This work presents the detection of hypoxanthine (HXA), a purine derivative that is similar to nucleic acids who overconsumption can cause health issues, by using hydrothermally synthesized cerium phosphate (CePO4) followed by a sonochemical approach for CePO4 decorated with a functionalized carbon nanofiber (CePO4@f-CNF) nanocomposite. The formation of the nanocomposite was confirmed with X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS). A CePO4@f-CNF nanocomposite is used to modify a glassy carbon electrode (GCE) to analyze the electrochemical detection of HXA. Cyclic voltammetry (CV), Electrochemical impedance spectroscopy (EIS), and Differential pulse voltammetry (DPV) were used to examine the electrochemical properties of the composite. As a result, the modified electrode exhibits a larger active surface area (A = 1.39 cm2), a low limit of detection (LOD) at 0.23 µM, a wide linear range (2.05–629 µM), and significant sensitivity. Therefore, the CePO4@f-CNF nanocomposite was used to study the real-time detection in chicken and fish samples, and it depicted significant results.
{"title":"Hydrothermally Synthesized Cerium Phosphate with Functionalized Carbon Nanofiber Nanocomposite for Enhanced Electrochemical Detection of Hypoxanthine","authors":"Prashant K. Kasare, Sea-Fue Wang","doi":"10.3390/chemosensors12050084","DOIUrl":"https://doi.org/10.3390/chemosensors12050084","url":null,"abstract":"This work presents the detection of hypoxanthine (HXA), a purine derivative that is similar to nucleic acids who overconsumption can cause health issues, by using hydrothermally synthesized cerium phosphate (CePO4) followed by a sonochemical approach for CePO4 decorated with a functionalized carbon nanofiber (CePO4@f-CNF) nanocomposite. The formation of the nanocomposite was confirmed with X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS). A CePO4@f-CNF nanocomposite is used to modify a glassy carbon electrode (GCE) to analyze the electrochemical detection of HXA. Cyclic voltammetry (CV), Electrochemical impedance spectroscopy (EIS), and Differential pulse voltammetry (DPV) were used to examine the electrochemical properties of the composite. As a result, the modified electrode exhibits a larger active surface area (A = 1.39 cm2), a low limit of detection (LOD) at 0.23 µM, a wide linear range (2.05–629 µM), and significant sensitivity. Therefore, the CePO4@f-CNF nanocomposite was used to study the real-time detection in chicken and fish samples, and it depicted significant results.","PeriodicalId":10057,"journal":{"name":"Chemosensors","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140969496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-11DOI: 10.3390/chemosensors12050081
Maria I. Pilo, G. Sanna, Nadia Spano
Conducting polymers are used in a wide range of applications, especially in the design and development of electrochemical sensors. Their main advantage, in this context, is their ability to efficiently modify an electrode surface using the direct polymerization of a suitable monomer in an electrochemical cell, or by physical coating. Additionally, the conducting polymers can be mixed with further materials (metal nanoparticles, carbonaceous materials) to enhance conductivity and analytical features (linear range, limit of detection, sensitivity, and selectivity). Due to their characteristics, conducting polymer-based amperometric sensors are applied to the determination of different organic and inorganic analytes. A view of recent advances in this field focusing on pyrrole, thiophene, and 3,4-ethylenedioxythiophene as starting materials is reported.
{"title":"Conducting Polymers in Amperometric Sensors: A State of the Art over the Last 15 Years with a Focus on Polypyrrole-, Polythiophene-, and Poly(3,4-ethylenedioxythiophene)-Based Materials","authors":"Maria I. Pilo, G. Sanna, Nadia Spano","doi":"10.3390/chemosensors12050081","DOIUrl":"https://doi.org/10.3390/chemosensors12050081","url":null,"abstract":"Conducting polymers are used in a wide range of applications, especially in the design and development of electrochemical sensors. Their main advantage, in this context, is their ability to efficiently modify an electrode surface using the direct polymerization of a suitable monomer in an electrochemical cell, or by physical coating. Additionally, the conducting polymers can be mixed with further materials (metal nanoparticles, carbonaceous materials) to enhance conductivity and analytical features (linear range, limit of detection, sensitivity, and selectivity). Due to their characteristics, conducting polymer-based amperometric sensors are applied to the determination of different organic and inorganic analytes. A view of recent advances in this field focusing on pyrrole, thiophene, and 3,4-ethylenedioxythiophene as starting materials is reported.","PeriodicalId":10057,"journal":{"name":"Chemosensors","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140988337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-11DOI: 10.3390/chemosensors12050080
Xi Zhang, Yunyi Zhang, Yuwei Gu, Junyu Zhou, Ming Li, Jian Qi
As a necessary sulfhydryl amino acid, L-cysteine (L-Cys) maintains many physiological functions in the biological system. However, abnormal L-Cys levels can cause a variety of diseases. In our work, a highly sensitive and selective assay has been developed for sensing L-Cys using the morphological transformation of silver-based materials induced by Cr3+. In this sensing system, Cr3+ could etch the silver nanoflakes into silver nanoparticles, accompanied by a change in absorbance, which decreases at 395 nm, creates a new peak at 538 nm, and keeps increasing the absorbance with the addition of Cr3+ concentration. Meanwhile, under the naked eye, the solution color changes from bright yellow to dark purple. Because of the strong affinity between L-Cys and Cr3+, L-Cys could inhibit the induction of Cr3+ on silver-based materials, thereby preventing changes in the configuration, absorption spectrum, and color of silver-based materials. Taking advantage of this point, we can quantitatively detect the concentration of L-Cys. A linear relationship between the absorbance ratio (A538 nm/A395 nm) and L-Cys concentration was found in the range of 0.1–0.9 μM, and the detection limit was 41.2 nM. The strategy was applied to measure L-Cys spiked in beer and urine samples, with recovery from 93.80 to 104.03% and 93.33% to 107.14% and RSD from 0.89 to 2.40% and 1.80% to 6.78%, respectively. This detection strategy demonstrates excellent selectivity and sensitivity, which makes it a practical and effective method for the detection of L-Cys in real samples.
{"title":"A Naked-Eye Colorimetric Ratio Method for the Selective and Sensitive Detection of L-Cys Based on a Silver Nanoflakes–Chromium (III) Ion System","authors":"Xi Zhang, Yunyi Zhang, Yuwei Gu, Junyu Zhou, Ming Li, Jian Qi","doi":"10.3390/chemosensors12050080","DOIUrl":"https://doi.org/10.3390/chemosensors12050080","url":null,"abstract":"As a necessary sulfhydryl amino acid, L-cysteine (L-Cys) maintains many physiological functions in the biological system. However, abnormal L-Cys levels can cause a variety of diseases. In our work, a highly sensitive and selective assay has been developed for sensing L-Cys using the morphological transformation of silver-based materials induced by Cr3+. In this sensing system, Cr3+ could etch the silver nanoflakes into silver nanoparticles, accompanied by a change in absorbance, which decreases at 395 nm, creates a new peak at 538 nm, and keeps increasing the absorbance with the addition of Cr3+ concentration. Meanwhile, under the naked eye, the solution color changes from bright yellow to dark purple. Because of the strong affinity between L-Cys and Cr3+, L-Cys could inhibit the induction of Cr3+ on silver-based materials, thereby preventing changes in the configuration, absorption spectrum, and color of silver-based materials. Taking advantage of this point, we can quantitatively detect the concentration of L-Cys. A linear relationship between the absorbance ratio (A538 nm/A395 nm) and L-Cys concentration was found in the range of 0.1–0.9 μM, and the detection limit was 41.2 nM. The strategy was applied to measure L-Cys spiked in beer and urine samples, with recovery from 93.80 to 104.03% and 93.33% to 107.14% and RSD from 0.89 to 2.40% and 1.80% to 6.78%, respectively. This detection strategy demonstrates excellent selectivity and sensitivity, which makes it a practical and effective method for the detection of L-Cys in real samples.","PeriodicalId":10057,"journal":{"name":"Chemosensors","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140988622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-09DOI: 10.3390/chemosensors12050079
A. I. Said, D. Staneva, E. Vasileva-Tonkova, Petar Grozdanov, I. Nikolova, R. Stoyanova, Albena Jordanova, I. Grabchev
A new water-soluble polyamidoamine (PAMAM) dendrimer modified with 4-sulfo-1,8-naphthalimide (DSNI) and its monomeric structural analogue (MSDI) were synthesized. Their photophysical properties were investigated in organic solvents of different polarities and aqueous solutions. The effect of pH on fluorescence intensity was determined. It was found that the dendrimer emits blue fluorescence in an acidic medium, which is quenched in an alkaline environment. This phenomenon is due to the possibility of suppression of nonradiative photoinduced electron transfer in acidic media. The influence of different metal ions (Cu2+, Pb2+, Sn2+, Sr2+, Mg2+, Ba2+, Co2+, Hg2+, Zn2+, Ni2+, Fe3+, Al3+) and anions (CN−, S2−, S2O52−, HPO42−, H2PO4−, F−, CH3COO−, NO2−, CO32−, SO42−) on the intensity of the emitted fluorescence was studied. Quenching was only found in the presence of Cu2+. This makes the dendrimer suitable for determining copper ions in water solutions in the presence of other metal ions and anions. Additionally, DSNI was used as a ligand to obtain a stable copper complex, the structure of which was investigated by electron paramagnetic resonance (EPR), infrared spectrum, and elemental analysis. Two copper ions were found to form a complex with one dendrimer. The in vitro microbiological activity of the new compounds against bacteria Pseudomonas aeruginosa and two viruses HRSV-2 and HAdV-5 was investigated. With a view to obtaining antibacterial and anti-viral textiles, cotton fabrics were treated with the three compounds, and then their activity against the same microbial strains was investigated. It was found that the microbiological activity was preserved after the application of the new compounds to the cotton fabrics.
{"title":"Synthesis, Spectral Characteristics, Sensing Properties and Microbiological Activity of New Water-Soluble 4-Sulfo-1,8-naphthalimides","authors":"A. I. Said, D. Staneva, E. Vasileva-Tonkova, Petar Grozdanov, I. Nikolova, R. Stoyanova, Albena Jordanova, I. Grabchev","doi":"10.3390/chemosensors12050079","DOIUrl":"https://doi.org/10.3390/chemosensors12050079","url":null,"abstract":"A new water-soluble polyamidoamine (PAMAM) dendrimer modified with 4-sulfo-1,8-naphthalimide (DSNI) and its monomeric structural analogue (MSDI) were synthesized. Their photophysical properties were investigated in organic solvents of different polarities and aqueous solutions. The effect of pH on fluorescence intensity was determined. It was found that the dendrimer emits blue fluorescence in an acidic medium, which is quenched in an alkaline environment. This phenomenon is due to the possibility of suppression of nonradiative photoinduced electron transfer in acidic media. The influence of different metal ions (Cu2+, Pb2+, Sn2+, Sr2+, Mg2+, Ba2+, Co2+, Hg2+, Zn2+, Ni2+, Fe3+, Al3+) and anions (CN−, S2−, S2O52−, HPO42−, H2PO4−, F−, CH3COO−, NO2−, CO32−, SO42−) on the intensity of the emitted fluorescence was studied. Quenching was only found in the presence of Cu2+. This makes the dendrimer suitable for determining copper ions in water solutions in the presence of other metal ions and anions. Additionally, DSNI was used as a ligand to obtain a stable copper complex, the structure of which was investigated by electron paramagnetic resonance (EPR), infrared spectrum, and elemental analysis. Two copper ions were found to form a complex with one dendrimer. The in vitro microbiological activity of the new compounds against bacteria Pseudomonas aeruginosa and two viruses HRSV-2 and HAdV-5 was investigated. With a view to obtaining antibacterial and anti-viral textiles, cotton fabrics were treated with the three compounds, and then their activity against the same microbial strains was investigated. It was found that the microbiological activity was preserved after the application of the new compounds to the cotton fabrics.","PeriodicalId":10057,"journal":{"name":"Chemosensors","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140997503","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：