Pub Date : 2024-10-16DOI: 10.1016/j.snb.2024.136783
Krishna Kiran Pawar, Tae-Un Kim, Ali Mirzaei, Pramod S. Patil, Hyoun Woo Kim, Sang Sub Kim
Acetone (C3H6O) is key member of the volatile organic compound family, which can cause health as well as environmental issues. The identification and sensing of acetone gas are important in many applications such as air quality control and biomarker-based diagnosis. Here, we synthesized hollow CuO/Cu2O octahedrons heterostructure composite through coprecipitation and subsequent heat treatment. The sensor manifested a response of 3.52 to 50 ppm acetone gas at 350 °C. Besides, it showed excellent stability in a 150-day test and excellent repeatability, with a response of 4.15. Also, exhaled gas sensing was carried out using standard method to estimate the acetone concentration in breath. The high sensing capability of the sensor was ascribed to the formation of p-p heterojunctions, the hollow morphology of octahedrons, and the presence of structural defects. The hollow CuO/Cu2O octahedron sensor with good performance may be employed for the detection and monitoring of acetone gas in real situations.
{"title":"Hollow CuO/Cu2O octahedrons for selective and stable detection of acetone gas","authors":"Krishna Kiran Pawar, Tae-Un Kim, Ali Mirzaei, Pramod S. Patil, Hyoun Woo Kim, Sang Sub Kim","doi":"10.1016/j.snb.2024.136783","DOIUrl":"https://doi.org/10.1016/j.snb.2024.136783","url":null,"abstract":"Acetone (C<sub>3</sub>H<sub>6</sub>O) is key member of the volatile organic compound family, which can cause health as well as environmental issues. The identification and sensing of acetone gas are important in many applications such as air quality control and biomarker-based diagnosis. Here, we synthesized hollow CuO/Cu<sub>2</sub>O octahedrons heterostructure composite through coprecipitation and subsequent heat treatment. The sensor manifested a response of 3.52 to 50 ppm acetone gas at 350 °C. Besides, it showed excellent stability in a 150-day test and excellent repeatability, with a response of 4.15. Also, exhaled gas sensing was carried out using standard method to estimate the acetone concentration in breath. The high sensing capability of the sensor was ascribed to the formation of p-p heterojunctions, the hollow morphology of octahedrons, and the presence of structural defects. The hollow CuO/Cu<sub>2</sub>O octahedron sensor with good performance may be employed for the detection and monitoring of acetone gas in real situations.","PeriodicalId":425,"journal":{"name":"Sensors and Actuators B: Chemical","volume":null,"pages":null},"PeriodicalIF":8.4,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142440002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-16DOI: 10.1016/j.snb.2024.136770
A recent Research article in this journal by Ouyang and co-workers (Sens. Actuators, B 393 (2023) 134260) reported a novel cobalt porphyrin-based upconversion fluorescence nanosensor to detect N-nitrosodimethylamine. However, Ouyang et al. did not properly present the mechanism of interaction between the nanosensor and the analyte in the context of cobalt porphyrin moiety based on previous literature reports. Moreover, they did not properly determine the structure of the presented nanosensor in the context of cobalt porphyrin moiety as evidenced by our spectroscopic data and previous literature reports. In addition, the interaction of the presented nanosensor with acidic and basic species, that can be present in N-nitrosodimethylamine or can originate from the sample, was not investigated. All this puts the structure and assigned sensing ability of the porphyrin-based fluorescence nanosensor under question.
Ouyang 及其合作者最近在该期刊上发表的一篇研究文章（Sens.Actuators, B 393 (2023) 134260）报道了一种新型的基于卟啉钴的上转换荧光纳米传感器，用于检测 N-亚硝基二甲胺。然而，Ouyang 等人并没有根据以往的文献报道，在卟啉钴分子的背景下正确阐述纳米传感器与分析物之间的相互作用机制。此外，根据我们的光谱数据和以前的文献报道，他们也没有正确确定所提出的卟啉钴纳米传感器的结构。此外，他们也没有研究该纳米传感器与酸性和碱性物质的相互作用，这些物质可能存在于 N-亚硝基二甲胺中，也可能来自样品。所有这些都对基于卟啉的荧光纳米传感器的结构和指定传感能力提出了质疑。
{"title":"Comment to the paper “Development of a novel upconversion fluorescence nanosensor based on metalloporphyrin element for sensitive detection of N-nitrosodimethylamine”","authors":"","doi":"10.1016/j.snb.2024.136770","DOIUrl":"10.1016/j.snb.2024.136770","url":null,"abstract":"<div><div>A recent Research article in this journal by Ouyang and co-workers (<em>Sens. Actuators, B</em> 393 (2023) 134260) reported a novel cobalt porphyrin-based upconversion fluorescence nanosensor to detect <em>N</em>-nitrosodimethylamine. However, Ouyang et al. did not properly present the mechanism of interaction between the nanosensor and the analyte in the context of cobalt porphyrin moiety based on previous literature reports. Moreover, they did not properly determine the structure of the presented nanosensor in the context of cobalt porphyrin moiety as evidenced by our spectroscopic data and previous literature reports. In addition, the interaction of the presented nanosensor with acidic and basic species, that can be present in <em>N</em>-nitrosodimethylamine or can originate from the sample, was not investigated. All this puts the structure and assigned sensing ability of the porphyrin-based fluorescence nanosensor under question.</div></div>","PeriodicalId":425,"journal":{"name":"Sensors and Actuators B: Chemical","volume":null,"pages":null},"PeriodicalIF":8.0,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142440001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-15DOI: 10.1016/j.snb.2024.136776
Chronic kidney disease (CKD) can greatly increase the mortality risk for clinical patients, with a major challenge being the accurate detection of uremic toxins. Metal organic frameworks (MOFs)-based colorimetry/fluorescence dual-mode probe have shown great potential for bio-detection. However, one of the challenges for MOFs-based nanoprobe is to effectively improve the activity of mimetic enzymes for colorimetric assays while maintaining their outstanding luminescence response for fluorescence sensing. Here, we developed a novel bimetallic Zr/Ce-MOFs, which possesses high catalytic activity and excellent luminescence properties for dual-mode sensing of uremic toxins. The co-existence of Ce and Zr in the MOFs improves the catalytic activity for colorimetric detection of phosphate ions (one type of uremic toxins) and the strong coordinate covalent interaction between phosphate ions and Zr/Ce leads to a significant fluorescence enhancement of the MOFs. Furthermore, we achieved high sensitivity phosphate ions analysis in serum samples. This strategy provides an easy and reliable platform for the detection of uremic toxins in complicated physiological environment.
{"title":"Bimetallic metal organic frameworks-based nanozyme for colorimetry/fluorescence dual-mode uremic toxin detection","authors":"","doi":"10.1016/j.snb.2024.136776","DOIUrl":"10.1016/j.snb.2024.136776","url":null,"abstract":"<div><div>Chronic kidney disease (CKD) can greatly increase the mortality risk for clinical patients, with a major challenge being the accurate detection of uremic toxins. Metal organic frameworks (MOFs)-based colorimetry/fluorescence dual-mode probe have shown great potential for bio-detection. However, one of the challenges for MOFs-based nanoprobe is to effectively improve the activity of mimetic enzymes for colorimetric assays while maintaining their outstanding luminescence response for fluorescence sensing. Here, we developed a novel bimetallic Zr/Ce-MOFs<sub>,</sub> which possesses high catalytic activity and excellent luminescence properties for dual-mode sensing of uremic toxins. The co-existence of Ce and Zr in the MOFs improves the catalytic activity for colorimetric detection of phosphate ions (one type of uremic toxins) and the strong coordinate covalent interaction between phosphate ions and Zr/Ce leads to a significant fluorescence enhancement of the MOFs. Furthermore, we achieved high sensitivity phosphate ions analysis in serum samples. This strategy provides an easy and reliable platform for the detection of uremic toxins in complicated physiological environment.</div></div>","PeriodicalId":425,"journal":{"name":"Sensors and Actuators B: Chemical","volume":null,"pages":null},"PeriodicalIF":8.0,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142436225","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-15DOI: 10.1016/j.snb.2024.136691
Reliable indicators to assess embryo quality are critical for the in vitro fertilization. Increasing evidence suggests that elasticity is emerging as a potential marker to evaluate the early development of embryos. This paper introduces a 3D-printed microfluidic device to measure the elastic modulus of zebrafish embryos deformed in a circular constriction channel. Firstly, numerical simulation was performed to analyze the impact of inlet pressure, embryo size and constriction channel diameter on the maximum protrusion length of the embryo. Subsequently, the zebrafish embryos were deformed using the device to record the protrusion length which was automatically measured using U-net, before the power-law rheological model was employed to calculate the elastic modulus. Experiments showed the power-law exponent and embryo elasticity were stable as the inlet pressure was not less than 250 mbar. Embryo culturing after squeezes revealed that embryos could maintain normal development even after multiple squeezes at 150 mbar while higher pressure may be fatal. Afterward, the deformation of the yolk was found to increase elasticity by 60.4 % compared to cases where only the chorion envelope was deformed. Finally, the elasticity variation of zebrafish embryos was measured for 17 hours. It revealed that the elasticity initially increased from hour 1 to hour 7–10 and then returned to approximately the original value during culture from the cleavage to the segmentation stages. The system with the ability of precise and long-term assessment of embryo elasticity may find valuable application potentials in the mechanical evaluation and sorting of embryos.
{"title":"Quantification of elastic modulus variations during zebrafish embryo development using a 3D-printed microfluidic platform","authors":"","doi":"10.1016/j.snb.2024.136691","DOIUrl":"10.1016/j.snb.2024.136691","url":null,"abstract":"<div><div>Reliable indicators to assess embryo quality are critical for the in vitro fertilization. Increasing evidence suggests that elasticity is emerging as a potential marker to evaluate the early development of embryos. This paper introduces a 3D-printed microfluidic device to measure the elastic modulus of zebrafish embryos deformed in a circular constriction channel. Firstly, numerical simulation was performed to analyze the impact of inlet pressure, embryo size and constriction channel diameter on the maximum protrusion length of the embryo. Subsequently, the zebrafish embryos were deformed using the device to record the protrusion length which was automatically measured using U-net, before the power-law rheological model was employed to calculate the elastic modulus. Experiments showed the power-law exponent and embryo elasticity were stable as the inlet pressure was not less than 250 mbar. Embryo culturing after squeezes revealed that embryos could maintain normal development even after multiple squeezes at 150 mbar while higher pressure may be fatal. Afterward, the deformation of the yolk was found to increase elasticity by 60.4 % compared to cases where only the chorion envelope was deformed. Finally, the elasticity variation of zebrafish embryos was measured for 17 hours. It revealed that the elasticity initially increased from hour 1 to hour 7–10 and then returned to approximately the original value during culture from the cleavage to the segmentation stages. The system with the ability of precise and long-term assessment of embryo elasticity may find valuable application potentials in the mechanical evaluation and sorting of embryos.</div></div>","PeriodicalId":425,"journal":{"name":"Sensors and Actuators B: Chemical","volume":null,"pages":null},"PeriodicalIF":8.0,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142436227","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-15DOI: 10.1016/j.snb.2024.136780
The enzyme-linked immunosorbent assay (ELISA) stands as a pivotal instrument in diagnostics and biomedical research, widely used for the detection and quantification of specific proteins associated with diseases. Despite its critical role, ELISA's ability to identify low-concentration proteins remains a significant challenge, hindering its effectiveness in early diagnostics, an area of growing importance. This study introduces a novel approach termed nucleic acid-templated amplification (NATA) to enhance ELISA's sensitivity without significantly modifying the common practices of the present ELISA. Drawing inspiration from viral proliferation mechanisms, our approach integrates a cell-free protein synthesis step using DNA sequences that encode the target biomarkers. This approach enables an in situ 'amplification' of target proteins during ELISA, boosting their concentrations to detectable levels. Our results demonstrate a substantial enhancement in sensitivity, with ELISA now being able to detect protein biomarkers at femtomolar concentrations—approaching the sensitivity range typically reserved for PCR in nucleic acid analysis. This breakthrough not only broadens ELISA’s applicability in early disease diagnosis and monitoring therapeutic interventions but also marks a significant advancement in protein biomarker detection technology. With its modular design, our method also offers high versatility and sensitivity, offering an advanced approach for protein detection in clinical diagnostics and research.
{"title":"Revisiting ELISA with in situ amplification of biomarkers to boost its sensitivity","authors":"","doi":"10.1016/j.snb.2024.136780","DOIUrl":"10.1016/j.snb.2024.136780","url":null,"abstract":"<div><div>The enzyme-linked immunosorbent assay (ELISA) stands as a pivotal instrument in diagnostics and biomedical research, widely used for the detection and quantification of specific proteins associated with diseases. Despite its critical role, ELISA's ability to identify low-concentration proteins remains a significant challenge, hindering its effectiveness in early diagnostics, an area of growing importance. This study introduces a novel approach termed nucleic acid-templated amplification (NATA) to enhance ELISA's sensitivity without significantly modifying the common practices of the present ELISA. Drawing inspiration from viral proliferation mechanisms, our approach integrates a cell-free protein synthesis step using DNA sequences that encode the target biomarkers. This approach enables an <em>in situ</em> 'amplification' of target proteins during ELISA, boosting their concentrations to detectable levels. Our results demonstrate a substantial enhancement in sensitivity, with ELISA now being able to detect protein biomarkers at femtomolar concentrations—approaching the sensitivity range typically reserved for PCR in nucleic acid analysis. This breakthrough not only broadens ELISA’s applicability in early disease diagnosis and monitoring therapeutic interventions but also marks a significant advancement in protein biomarker detection technology. With its modular design, our method also offers high versatility and sensitivity, offering an advanced approach for protein detection in clinical diagnostics and research.</div></div>","PeriodicalId":425,"journal":{"name":"Sensors and Actuators B: Chemical","volume":null,"pages":null},"PeriodicalIF":8.0,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142436275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-14DOI: 10.1016/j.snb.2024.136717
Silk cocoons were used as a bioelectrode for the wearable electrochemical sensors of sweat lactate via carbonization and the in situ electrodeposition of platinum nanoparticles (PtNPs) and reduced graphene oxide (rGO), followed by lactate oxidase immobilization. Scanning electron microscopy, atomic force microscopy, and x-ray photoelectron microscopy confirmed that PtNPs/rGO were deposited on the carbonized silk cocoon surfaces, characterized via the physical and chemical alterations of silk cocoons. The electrocatalytic activity of PtNPs and the high surface area and functionality of rGO enhanced the electrochemical sensitivity of the sensor in lactate detection. This biosensor detected sweat lactate selectively in a range of 0–25 mM with a limit of detection of 0.07 mM, which is sufficient to distinguish between normal individuals and muscle fatigue-prone patients at a cut-off sweat lactate level of 12.5 mM. This biosensor was applied for sweat lactate detection and validated through laser desorption–ionization mass spectrometry with satisfactory results. This bioelectrode exhibits cytocompatibility with non-irritation and non-allergy to human skin, highlighting its application as a wearable lactate biosensor for self-monitoring of muscle fatigue.
通过碳化和原位电沉积铂纳米颗粒（PtNPs）和还原氧化石墨烯（rGO），然后固定乳酸氧化酶，将蚕茧用作汗液乳酸可穿戴电化学传感器的生物电极。扫描电子显微镜、原子力显微镜和 X 射线光电子显微镜证实，PtNPs/rGO 沉积在碳化蚕茧表面，并通过蚕茧的物理和化学变化进行了表征。PtNPs 的电催化活性和 rGO 的高比表面积和功能性提高了传感器检测乳酸盐的电化学灵敏度。这种生物传感器可选择性地检测 0-25 mM 范围内的汗液乳酸盐，检测限为 0.07 mM，足以区分正常人和肌肉易疲劳病人，其临界汗液乳酸盐水平为 12.5 mM。该生物传感器被应用于汗液乳酸盐检测，并通过激光解吸电离质谱法进行了验证，结果令人满意。该生物电极具有细胞兼容性，对人体皮肤无刺激、无过敏，可作为可穿戴乳酸生物传感器用于肌肉疲劳的自我监测。
{"title":"Novel bioelectrode for sweat lactate sensor based on platinum nanoparticles/reduced graphene oxide modified carbonized silk cocoon","authors":"","doi":"10.1016/j.snb.2024.136717","DOIUrl":"10.1016/j.snb.2024.136717","url":null,"abstract":"<div><div>Silk cocoons were used as a bioelectrode for the wearable electrochemical sensors of sweat lactate via carbonization and the in situ electrodeposition of platinum nanoparticles (PtNPs) and reduced graphene oxide (rGO), followed by lactate oxidase immobilization. Scanning electron microscopy, atomic force microscopy, and x-ray photoelectron microscopy confirmed that PtNPs/rGO were deposited on the carbonized silk cocoon surfaces, characterized via the physical and chemical alterations of silk cocoons. The electrocatalytic activity of PtNPs and the high surface area and functionality of rGO enhanced the electrochemical sensitivity of the sensor in lactate detection. This biosensor detected sweat lactate selectively in a range of 0–25 mM with a limit of detection of 0.07 mM, which is sufficient to distinguish between normal individuals and muscle fatigue-prone patients at a cut-off sweat lactate level of 12.5 mM. This biosensor was applied for sweat lactate detection and validated through laser desorption–ionization mass spectrometry with satisfactory results. This bioelectrode exhibits cytocompatibility with non-irritation and non-allergy to human skin, highlighting its application as a wearable lactate biosensor for self-monitoring of muscle fatigue.</div></div>","PeriodicalId":425,"journal":{"name":"Sensors and Actuators B: Chemical","volume":null,"pages":null},"PeriodicalIF":8.0,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142431803","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-14DOI: 10.1016/j.snb.2024.136775
The electric field is a fundamental physical quantity that determines the characteristics or behavior of charged materials in liquids. The precise characterization of charged materials involving nanoparticles or biomaterials such as cells and extracellular vesicles (EVs) requires a rigorous calculation of the electric field applied to these materials. However, unlike solid-state materials, the precise measurement of the electric field applied in liquids is challenging because of liquid-electrode interface resistance and non-uniform electric-field regions near electrodes. This study proposes a method for determining the precise electric field in liquids using the van der Pauw measurement technique. The conductivity of the liquid was measured using a microfluidic channel with a van der Pauw configuration. The electric field in the liquid was then calculated based on the relationship between the conductivity and current density. The accuracy of the proposed method was verified by measuring the conductivity of standard solutions and phosphate-buffered saline (PBS), followed by determining the electric field applied to the nanoparticles in these solutions. In addition, the proposed method was used to determine the zeta potential of charged nanoparticles. This simple method for determining liquid conductivity and calculating electric fields in liquids could be effectively used for various electrochemical studies.
{"title":"Precise determination of electric field applied to charged materials in liquid via van der Pauw technique","authors":"","doi":"10.1016/j.snb.2024.136775","DOIUrl":"10.1016/j.snb.2024.136775","url":null,"abstract":"<div><div>The electric field is a fundamental physical quantity that determines the characteristics or behavior of charged materials in liquids. The precise characterization of charged materials involving nanoparticles or biomaterials such as cells and extracellular vesicles (EVs) requires a rigorous calculation of the electric field applied to these materials. However, unlike solid-state materials, the precise measurement of the electric field applied in liquids is challenging because of liquid-electrode interface resistance and non-uniform electric-field regions near electrodes. This study proposes a method for determining the precise electric field in liquids using the van der Pauw measurement technique. The conductivity of the liquid was measured using a microfluidic channel with a van der Pauw configuration. The electric field in the liquid was then calculated based on the relationship between the conductivity and current density. The accuracy of the proposed method was verified by measuring the conductivity of standard solutions and phosphate-buffered saline (PBS), followed by determining the electric field applied to the nanoparticles in these solutions. In addition, the proposed method was used to determine the zeta potential of charged nanoparticles. This simple method for determining liquid conductivity and calculating electric fields in liquids could be effectively used for various electrochemical studies.</div></div>","PeriodicalId":425,"journal":{"name":"Sensors and Actuators B: Chemical","volume":null,"pages":null},"PeriodicalIF":8.0,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142431707","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-13DOI: 10.1016/j.snb.2024.136749
Nowadays, the role of humidity is a major factor in numerous applications such as medical purposes and soil moisture detection. In this work, we synthesized pristine LaFeO3 (LFO1, LFO2) nanoparticles via hydrothermal method with and without urea. Furthermore, the synthesis of LFO doped with Cr, Cu and Mn was also done in the presence of urea using hydrothermal technique and studied for humidity sensing. The XRD confirms the crystalline size of the developed nanoparticles ranges in 19–25 nm. The sensing properties of pristine and doped LFO sensors for humidity sensing have been investigated in the 11 % – 90 % relative humidity (RH) range. As compared with others, the Cu-doped LFO sensor exhibits better response and recovery time of 5.4 s and 3.8 s respectively. Additionally, the nanoparticles of Cu-doped LFO show a highly porous nature having nano-perforated dumbbell structure as identified from the FESEM images. Moreover, to check the functionality of the developed sensor, the device is fabricated, resulting in the linear increase in output current with increase in relative humidity at a bias voltage of 1 V. With rapid response and recovery time, superior sensitivity and long-time stability, the developed Cu-doped LFO sensor can be used for medical detection of asthma, apnea and cough, as well as for non-contact skin monitoring that indicates its potential use to identify the moisturizing products for skin care. Finally, the efficacy of the fabricated sensor to monitor real-time humidity is also observed via IoT on a laptop/smartphone to display its potential to detect soil moisture for agriculture application.
{"title":"Urea modified Cu-doped LaFeO3 nano-particles for humidity sensing with contactless moisture detection for medical and agricultural application","authors":"","doi":"10.1016/j.snb.2024.136749","DOIUrl":"10.1016/j.snb.2024.136749","url":null,"abstract":"<div><div>Nowadays, the role of humidity is a major factor in numerous applications such as medical purposes and soil moisture detection. In this work, we synthesized pristine LaFeO<sub>3</sub> (LFO1, LFO2) nanoparticles via hydrothermal method with and without urea. Furthermore, the synthesis of LFO doped with Cr, Cu and Mn was also done in the presence of urea using hydrothermal technique and studied for humidity sensing. The XRD confirms the crystalline size of the developed nanoparticles ranges in 19–25 nm. The sensing properties of pristine and doped LFO sensors for humidity sensing have been investigated in the 11 % – 90 % relative humidity (RH) range. As compared with others, the Cu-doped LFO sensor exhibits better response and recovery time of 5.4 s and 3.8 s respectively. Additionally, the nanoparticles of Cu-doped LFO show a highly porous nature having nano-perforated dumbbell structure as identified from the FESEM images. Moreover, to check the functionality of the developed sensor, the device is fabricated, resulting in the linear increase in output current with increase in relative humidity at a bias voltage of 1 V. With rapid response and recovery time, superior sensitivity and long-time stability, the developed Cu-doped LFO sensor can be used for medical detection of asthma, apnea and cough, as well as for non-contact skin monitoring that indicates its potential use to identify the moisturizing products for skin care. Finally, the efficacy of the fabricated sensor to monitor real-time humidity is also observed via IoT on a laptop/smartphone to display its potential to detect soil moisture for agriculture application.</div></div>","PeriodicalId":425,"journal":{"name":"Sensors and Actuators B: Chemical","volume":null,"pages":null},"PeriodicalIF":8.0,"publicationDate":"2024-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142431273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-13DOI: 10.1016/j.snb.2024.136773
Acetone, a common volatile organic compound (VOC), poses health risks even at low concentrations. Current acetone sensors are costly and require specialized equipment and expertize. This work develops a novel vapor sensor for determining acetone vapor concentration using the speckle patterns generated by liquid crystal gels (LCGs). The vapor sensor comprises a LCG film prepared by the phase separation of a mixture containing polystyrene microspheres and liquid crystals (LCs). The orientation of the LC molecules changes when the LCG film is exposed to an acetone vapor environment, altering the equivalent refractive indices of the LC domains. This leads to a change in the scattering state of the LCG film under laser illumination, forming different speckle patterns. The concentration of acetone vapor is determined by calculating the correlation coefficient of the speckle images, where the sensitivity and limit of detection of the sensor are 4 × 10−4 ppm−1 and 754.05 ppm, respectively. The developed correlated laser speckle-based optical system is simpler, less expensive, and more stable than traditional LC film vapor sensors. This acetone gas sensor has potential applications in industrial and indoor air quality testing.
{"title":"Liquid crystal gel-based acetone sensor using correlated laser speckles","authors":"","doi":"10.1016/j.snb.2024.136773","DOIUrl":"10.1016/j.snb.2024.136773","url":null,"abstract":"<div><div>Acetone, a common volatile organic compound (VOC), poses health risks even at low concentrations. Current acetone sensors are costly and require specialized equipment and expertize. This work develops a novel vapor sensor for determining acetone vapor concentration using the speckle patterns generated by liquid crystal gels (LCGs). The vapor sensor comprises a LCG film prepared by the phase separation of a mixture containing polystyrene microspheres and liquid crystals (LCs). The orientation of the LC molecules changes when the LCG film is exposed to an acetone vapor environment, altering the equivalent refractive indices of the LC domains. This leads to a change in the scattering state of the LCG film under laser illumination, forming different speckle patterns. The concentration of acetone vapor is determined by calculating the correlation coefficient of the speckle images, where the sensitivity and limit of detection of the sensor are 4 × 10<sup>−4</sup> ppm<sup>−1</sup> and 754.05 ppm, respectively. The developed correlated laser speckle-based optical system is simpler, less expensive, and more stable than traditional LC film vapor sensors. This acetone gas sensor has potential applications in industrial and indoor air quality testing.</div></div>","PeriodicalId":425,"journal":{"name":"Sensors and Actuators B: Chemical","volume":null,"pages":null},"PeriodicalIF":8.0,"publicationDate":"2024-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142430464","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-13DOI: 10.1016/j.snb.2024.136753
Min Liu, Shanshan Wei, Yuxin Xie, Kaihua Su, Xiangyu Yin, Xuewei Song, Kaixin Hu, Guoying Sun, Yibing Liu
The persistent residual of tetracycline (TC) in animal-derived food has posed a significant threat to human health, so the sensitive and specific detection of TC has extraordinary significance for food quality evaluation. However, most current methods were inevitably interfered by the highly similar structures of TCs family. To improve the specificity of TC detection, a novel ratiometric fluorescence sensor based on chiral europium-doped carbon dots (Eu-L/D-CDs) was designed for the sensing of TC. The blue fluorescence of Eu-L/D-CDs could be reduced by TC through static quenching (SQE) and internal filtering effects (IFE), while the red fluorescence could be enhanced through antenna effect (AE). The sensor achieved the rapid and sensitive detection of TC through fluorescence and colorimetric methods with detection limits as low as 2.82 nM and 3.74 nM, respectively. Importantly, the Eu-L-CDs-loaded test strips and hydrogel microspheres achieved the portable and visual detection of TC with the assistance of smartphone sensing platform. Additionally, the sensor could rapidly screen TC adjuvants in bacteria, providing a new approach to enhance the sensitivity of resistant bacteria to drugs. Therefore, this sensor not only proposed new insights into the sensitive and portable monitoring of TC, but also expanded the application of chiral CDs in the fields of biomedical sensing.
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