Pub Date : 2025-01-01DOI: 10.1016/j.sintl.2025.100337
Artem Eliseev , Vladimir Korolev , Evgeny Anokhin , Andrei Chumakov , Alexander Vasiliev , Lev Trusov , Pavel Kazin , Andrei Eliseev
The paper reports on the application of hard magnetic nanoplatelets for direct local dynamic viscosity evaluation in liquids through their drag-hindered rotation after a magnetic field. Strontium hexaferrite, SrFe12O19 nanoplatelets with a diameter of 50 nm and a thickness of 5 nm were employed as nanoscale probes. The dynamics of nanoplatelets is investigated with AC magnetometry, small-angle X-ray scattering, and optical absorption/reflectance spectroscopy. Those reveal well-defined relation of drag force and phase lag tangent for platelets rotation under AC magnetization with the viscosity of the medium. The analytical quantitative description for magneto-optical response is provided and utilized successfully for independent viscosity evaluation of various liquids within the viscosity range of 0.5–1000 mPa∙s. The nanoscale size of the probes also enabled viscosity visualization with micrometer resolution in microchannels.
{"title":"Fast micrometer resolution magneto-optical viscosity measurements with hard magnetic nanoplatelets","authors":"Artem Eliseev , Vladimir Korolev , Evgeny Anokhin , Andrei Chumakov , Alexander Vasiliev , Lev Trusov , Pavel Kazin , Andrei Eliseev","doi":"10.1016/j.sintl.2025.100337","DOIUrl":"10.1016/j.sintl.2025.100337","url":null,"abstract":"<div><div>The paper reports on the application of hard magnetic nanoplatelets for direct local dynamic viscosity evaluation in liquids through their drag-hindered rotation after a magnetic field. Strontium hexaferrite, SrFe<sub>12</sub>O<sub>19</sub> nanoplatelets with a diameter of 50 nm and a thickness of 5 nm were employed as nanoscale probes. The dynamics of nanoplatelets is investigated with AC magnetometry, small-angle X-ray scattering, and optical absorption/reflectance spectroscopy. Those reveal well-defined relation of drag force and phase lag tangent for platelets rotation under AC magnetization with the viscosity of the medium. The analytical quantitative description for magneto-optical response is provided and utilized successfully for independent viscosity evaluation of various liquids within the viscosity range of 0.5–1000 mPa∙s. The nanoscale size of the probes also enabled viscosity visualization with micrometer resolution in microchannels.</div></div>","PeriodicalId":21733,"journal":{"name":"Sensors International","volume":"6 ","pages":"Article 100337"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143886591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-01DOI: 10.1016/j.sintl.2025.100334
Alaa Hussein Hilal, Ahmed Hameed Reja, Mohammed J. Mohammed
In the last decade, the number of drones has been increasing and becoming cheaper relative to the damage they can cause, threatening airports, transportation, and military applications. Jamming on drones is becoming more and more significant. Handheld anti-drone jammer antennas require high-gain directivity beam patterns with narrow half-power beam widths (HPBW) while also covering multiple frequency bands that are used by drones. This work has modified the proposed multiband gain and enhanced the narrow beam utilized by the Dual Ridge Horn Antenna (DRHA) to meet the requirements of drone jamming systems. The proposed antenna can cover GPS , 2.45 GHz, and 5.8 GHz. This work presents a DRHA developed utilizing CST Studio and optimized by using genetic algorithm optimization (GA) that has been employed to improve parameters that enhance selected frequencies. One of the standout features of this design is the incorporation of a dielectric microwave lens, which significantly improved the antenna factor This lens has been inventively crafted using three dielectric constant, 2.1, 4, and 4.2 at three different diameters 11 cm, 7 cm and 4 cm as well as different thickness 0.9 cm, 1.3 cm and 1.5 cm, respectively. According to impressive simulations the reflection coefficient has been improved from dB to an incredible dB at 2.45 GHz. Regarding to the Vector Network Analyzer (VNA) outcomes the practical design improved from dB to dB which reflecting a remarkable enhancement of 43.88% after integrating the dielectric lens. The final dimensions of the fabricated antenna, including the feed section, have been defined as (3.65 ), aligning excellently with relevant works. Finally, the practical design is an agreement match with simulation results, and the measured peak gain is 7.92 dB at 1.575 GHz, 10.9 dB at 2.45 GHz and 15 dB at 5.8 GHz. The proposed antenna would be suitable for use in a portable handheld jamming system on drones.
{"title":"Modify a dual ridge horn antenna for drone jamming applications","authors":"Alaa Hussein Hilal, Ahmed Hameed Reja, Mohammed J. Mohammed","doi":"10.1016/j.sintl.2025.100334","DOIUrl":"10.1016/j.sintl.2025.100334","url":null,"abstract":"<div><div>In the last decade, the number of drones has been increasing and becoming cheaper relative to the damage they can cause, threatening airports, transportation, and military applications. Jamming on drones is becoming more and more significant. Handheld anti-drone jammer antennas require high-gain directivity beam patterns with narrow half-power beam widths (HPBW) while also covering multiple frequency bands that are used by drones. This work has modified the proposed multiband gain and enhanced the narrow beam utilized by the Dual Ridge Horn Antenna (DRHA) to meet the requirements of drone jamming systems. The proposed antenna can cover GPS <span><math><msub><mrow><mi>L</mi></mrow><mrow><mn>1</mn></mrow></msub></math></span>, 2.45 GHz, and 5.8 GHz. This work presents a DRHA developed utilizing CST Studio and optimized by using genetic algorithm optimization (GA) that has been employed to improve parameters that enhance selected frequencies. One of the standout features of this design is the incorporation of a dielectric microwave lens, which significantly improved the antenna factor This lens has been inventively crafted using three dielectric constant, <span><math><msub><mrow><mi>ɛ</mi></mrow><mrow><mi>r</mi></mrow></msub></math></span> 2.1, 4, and 4.2 at three different diameters 11 cm, 7 cm and 4 cm as well as different thickness 0.9 cm, 1.3 cm and 1.5 cm, respectively. According to impressive simulations the reflection coefficient has been improved from <span><math><mrow><mo>−</mo><mn>12</mn><mo>.</mo><mn>13</mn></mrow></math></span> dB to an incredible <span><math><mrow><mo>−</mo><mn>19</mn><mo>.</mo><mn>7</mn></mrow></math></span> dB at 2.45 GHz. Regarding to the Vector Network Analyzer (VNA) outcomes the practical design improved from <span><math><mrow><mo>−</mo><mn>8</mn><mo>.</mo><mn>25</mn></mrow></math></span> dB to <span><math><mrow><mo>−</mo><mn>18</mn><mo>.</mo><mn>8</mn></mrow></math></span> dB which reflecting a remarkable enhancement of 43.88% after integrating the dielectric lens. The final dimensions of the fabricated antenna, including the feed section, have been defined as (3.65<span><math><mi>λ</mi></math></span> <span><math><mrow><mo>×</mo><mn>2</mn><mi>λ</mi></mrow></math></span> <span><math><mrow><mo>×</mo><mn>2</mn><mi>λ</mi></mrow></math></span>), aligning excellently with relevant works. Finally, the practical design is an agreement match with simulation results, and the measured peak gain is 7.92 dB at 1.575 GHz, 10.9 dB at 2.45 GHz and 15 dB at 5.8 GHz. The proposed antenna would be suitable for use in a portable handheld jamming system on drones.</div></div>","PeriodicalId":21733,"journal":{"name":"Sensors International","volume":"6 ","pages":"Article 100334"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143886479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-01DOI: 10.1016/j.sintl.2025.100344
Johan A. Farfán, Mary Licuona, Betty C. Galarreta, Yulán Hernández
Nanomaterial-based biosensors provide high sensitivity and versatility for the detection of target analytes. Particularly, gold nanomaterials are widely employed as signal transducers due to their unique plasmonic properties. When functionalized with aptamers, these nanostructures gain enhanced selectivity, rapid response capability, and cost-effectiveness. However, the instability of large gold nanoparticles can hinder the exploration of various shapes and sizes.
In this research, two different types of nanoparticles were used for the development of a carcinoembryonic antigen (CEA), a tumoral biomarker for colorectal cancer, nanosensor. It was proposed a system based on gold nanotriangles (AuNTs) functionalized with the amphiphilic polymer polyvinylpyrrolidone (AuNT@PVP) and a hairpin-shaped aptamer selective to CEA biotinylated at the 3′ end and thiolated at the 5′ end (AuNT@PVP@Apt). Specific recognition process was optimized expecting that CEA would trigger the unfolding of the hairpin structure, exposing biotin moieties that enabled subsequent binding of streptavidin-functionalized gold nanoparticles (AuNP@Strept, 3–5 nm in diameter). However, when analyzing the optical changes observed by UV–Vis–NIR spectroscopy and its correlation with the concentration of CEA, it was observed that the main mechanism involved in the detection was a selective growth mechanism of AuNPs, leading to a really simple and easy way of detecting CEA. The results obtained in this study highlight the intricacies of developing such nanosensors and introduce a novel detection method based on a selective growth mechanism that can be further used for detection.
{"title":"Nanosensor for carcinoembryonic antigen (CEA) detection based on a selective growth-regulating mechanism","authors":"Johan A. Farfán, Mary Licuona, Betty C. Galarreta, Yulán Hernández","doi":"10.1016/j.sintl.2025.100344","DOIUrl":"10.1016/j.sintl.2025.100344","url":null,"abstract":"<div><div>Nanomaterial-based biosensors provide high sensitivity and versatility for the detection of target analytes. Particularly, gold nanomaterials are widely employed as signal transducers due to their unique plasmonic properties. When functionalized with aptamers, these nanostructures gain enhanced selectivity, rapid response capability, and cost-effectiveness. However, the instability of large gold nanoparticles can hinder the exploration of various shapes and sizes.</div><div>In this research, two different types of nanoparticles were used for the development of a carcinoembryonic antigen (CEA), a tumoral biomarker for colorectal cancer, nanosensor. It was proposed a system based on gold nanotriangles (AuNTs) functionalized with the amphiphilic polymer polyvinylpyrrolidone (AuNT@PVP) and a hairpin-shaped aptamer selective to CEA biotinylated at the 3′ end and thiolated at the 5′ end (AuNT@PVP@Apt). Specific recognition process was optimized expecting that CEA would trigger the unfolding of the hairpin structure, exposing biotin moieties that enabled subsequent binding of streptavidin-functionalized gold nanoparticles (AuNP@Strept, 3–5 nm in diameter). However, when analyzing the optical changes observed by UV–Vis–NIR spectroscopy and its correlation with the concentration of CEA, it was observed that the main mechanism involved in the detection was a selective growth mechanism of AuNPs, leading to a really simple and easy way of detecting CEA. The results obtained in this study highlight the intricacies of developing such nanosensors and introduce a novel detection method based on a selective growth mechanism that can be further used for detection.</div></div>","PeriodicalId":21733,"journal":{"name":"Sensors International","volume":"6 ","pages":"Article 100344"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144514161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The primary objective of this study was to develop KCl-leakage-free reference electrodes for biomedical, clinical, and food applications, as well as for use in the semiconductor industry. Accordingly, we developed new reference electrodes based on Ag2O–TeO2 glass and Ti, employing Ag2O–TeO2 glass/Ti and Ti/Ag2O–TeO2 glass/stainless steel (SUS) configurations in particular. The investigations revealed that the pH sensitivity of 25Ag2O·75TeO2/Ti (3 %) was significantly lower than that of 25Ag2O·75TeO2/SUS (12 %). Ag7Te4 observed in Ti samples had a higher Te fraction than Ag2Te observed in SUS samples. The stronger reducing ability of Ti compared to Fe in SUS facilitated the reduction of Te4+ ions to Te0, which subsequently reacted with Ag0. This observation supports the hypothesis that the pH sensitivity of Ag7Te4 is lower than that of Ag2Te. Heat treatment of Ti on 25Ag2O·75TeO2/SUS resulted in a gray TiO2/Ti layer surrounded by ocher-colored precipitates, including the Ag–Te alloy. Increasing the Ti content in Ti/25Ag2O·75TeO2/SUS reduced its pH sensitivity. A 1:2 Ti weight ratio achieved a pH sensitivity of 5 %, similar to 25Ag2O·75TeO2/Ti (3 %). Dividing Ti into three sections eliminated the central TiO2/Ti layer, leaving only Ag–Te alloys and TeO2 as the predominant materials. However, this structural modification had no discernible impact on the pH sensitivity. These findings suggest that Ag–Te alloys and TeO2 can act as primary pH-responsive sites, with TiO2/Ti having no significant contribution. Since TeO2 likely has a higher electrical resistivity than Ag–Te alloys, the observed low pH sensitivity results from that of the minor but electrically conductive Ag–Te alloys. Therefore, 25Ag2O·75TeO2/Ti is a promising candidate for developing KCl-leakage-free reference electrodes for pH sensors, offering low pH sensitivity.
{"title":"KCl-leakage-free reference electrode based on Ag2O–TeO2 glass and Ti","authors":"Tadanori Hashimoto , Masato Kano , Kyota Fujioka , Naoki Yasuda , Atsushi Ishihara , Takuhisa Komi , Yuji Nishio","doi":"10.1016/j.sintl.2025.100339","DOIUrl":"10.1016/j.sintl.2025.100339","url":null,"abstract":"<div><div>The primary objective of this study was to develop KCl-leakage-free reference electrodes for biomedical, clinical, and food applications, as well as for use in the semiconductor industry. Accordingly, we developed new reference electrodes based on Ag<sub>2</sub>O–TeO<sub>2</sub> glass and Ti, employing Ag<sub>2</sub>O–TeO<sub>2</sub> glass/Ti and Ti/Ag<sub>2</sub>O–TeO<sub>2</sub> glass/stainless steel (SUS) configurations in particular. The investigations revealed that the pH sensitivity of 25Ag<sub>2</sub>O·75TeO<sub>2</sub>/Ti (3 %) was significantly lower than that of 25Ag<sub>2</sub>O·75TeO<sub>2</sub>/SUS (12 %). Ag<sub>7</sub>Te<sub>4</sub> observed in Ti samples had a higher Te fraction than Ag<sub>2</sub>Te observed in SUS samples. The stronger reducing ability of Ti compared to Fe in SUS facilitated the reduction of Te<sup>4+</sup> ions to Te<sup>0</sup>, which subsequently reacted with Ag<sup>0</sup>. This observation supports the hypothesis that the pH sensitivity of Ag<sub>7</sub>Te<sub>4</sub> is lower than that of Ag<sub>2</sub>Te. Heat treatment of Ti on 25Ag<sub>2</sub>O·75TeO<sub>2</sub>/SUS resulted in a gray TiO<sub>2</sub>/Ti layer surrounded by ocher-colored precipitates, including the Ag–Te alloy. Increasing the Ti content in Ti/25Ag<sub>2</sub>O·75TeO<sub>2</sub>/SUS reduced its pH sensitivity. A 1:2 Ti weight ratio achieved a pH sensitivity of 5 %, similar to 25Ag<sub>2</sub>O·75TeO<sub>2</sub>/Ti (3 %). Dividing Ti into three sections eliminated the central TiO<sub>2</sub>/Ti layer, leaving only Ag–Te alloys and TeO<sub>2</sub> as the predominant materials. However, this structural modification had no discernible impact on the pH sensitivity. These findings suggest that Ag–Te alloys and TeO<sub>2</sub> can act as primary pH-responsive sites, with TiO<sub>2</sub>/Ti having no significant contribution. Since TeO<sub>2</sub> likely has a higher electrical resistivity than Ag–Te alloys, the observed low pH sensitivity results from that of the minor but electrically conductive Ag–Te alloys. Therefore, 25Ag<sub>2</sub>O·75TeO<sub>2</sub>/Ti is a promising candidate for developing KCl-leakage-free reference electrodes for pH sensors, offering low pH sensitivity.</div></div>","PeriodicalId":21733,"journal":{"name":"Sensors International","volume":"6 ","pages":"Article 100339"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144212349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-22DOI: 10.1016/j.sintl.2024.100312
P. Sriramani , N. Mohankumar , Lignesh Durai , Y. Prasamsha , Nitin Rakesh
This article introduces an analytical model for double-gate AlGaN/GaN MOS-HEMT biosensors to accurately detect pH analytes and charged biomolecules. The device incorporates nanocavities and operates on the concept of dielectric modulation, presuming the presence of a native oxide layer on the surface of the AlGaN layer. The pH of the analyte is represented as the interface charge. Numerical simulations evaluate the biosensor's effectiveness by analyzing its sensitivity to drain ON current (SI) and threshold voltage (SV). The device exhibited a peak SV of 586.5 mV, a value tenfold more significant than the Nernst limit for pH analyte. The maximum SI, computed at the peak transconductance, was determined to be 135.5 mA/mm/pH at VG = −2V and VD = 5V. The biosensor response to a charged biomolecule is assessed by considering the dielectric constant and charge density (ρ). The biosensor exhibited a maximum SI of 0.225 at VD = 5V and VG = −1V and SV of 1.488V for charged biomolecule at ρ = 1 × 1012/cm2. The impact of the bias voltages, ion molar concentration of pH analyte, AlGaN layer thickness and cavity length on the SI of the device is explored in detail. The SI for pH analytes is unaffected by the AlGaN layer thickness but enhanced with ion molar concentration and cavity length. However, for charged biomolecules, SI decreased with increased AlGaN layer thickness and improved with cavity length.
{"title":"Analytical model for DG-AlGaN/GaN MOS-HEMT for sensitive analysis of pH analytes and charged biomolecules","authors":"P. Sriramani , N. Mohankumar , Lignesh Durai , Y. Prasamsha , Nitin Rakesh","doi":"10.1016/j.sintl.2024.100312","DOIUrl":"10.1016/j.sintl.2024.100312","url":null,"abstract":"<div><div>This article introduces an analytical model for double-gate AlGaN/GaN MOS-HEMT biosensors to accurately detect pH analytes and charged biomolecules. The device incorporates nanocavities and operates on the concept of dielectric modulation, presuming the presence of a native oxide layer on the surface of the AlGaN layer. The pH of the analyte is represented as the interface charge. Numerical simulations evaluate the biosensor's effectiveness by analyzing its sensitivity to drain ON current (S<sub>I</sub>) and threshold voltage (S<sub>V</sub>). The device exhibited a peak S<sub>V</sub> of 586.5 mV, a value tenfold more significant than the Nernst limit for pH analyte. The maximum S<sub>I</sub>, computed at the peak transconductance, was determined to be 135.5 mA/mm/pH at V<sub>G</sub> = −2V and V<sub>D</sub> = 5V. The biosensor response to a charged biomolecule is assessed by considering the dielectric constant and charge density (ρ). The biosensor exhibited a maximum S<sub>I</sub> of 0.225 at V<sub>D</sub> = 5V and V<sub>G</sub> = −1V and S<sub>V</sub> of 1.488V for charged biomolecule at ρ = 1 × 10<sup>12</sup>/cm<sup>2</sup>. The impact of the bias voltages, ion molar concentration of pH analyte, AlGaN layer thickness and cavity length on the S<sub>I</sub> of the device is explored in detail. The S<sub>I</sub> for pH analytes is unaffected by the AlGaN layer thickness but enhanced with ion molar concentration and cavity length. However, for charged biomolecules, S<sub>I</sub> decreased with increased AlGaN layer thickness and improved with cavity length.</div></div>","PeriodicalId":21733,"journal":{"name":"Sensors International","volume":"6 ","pages":"Article 100312"},"PeriodicalIF":0.0,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142723833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-21DOI: 10.1016/j.sintl.2024.100310
AnnieCanisius D , Joselene Suzan Jennifer P , Joe Raja Ruban M , Davis Varghese , Gladys Joysi M , Muthupandi S , Madhavan J , Victor Antony Raj M , Saravanan Muthupandian
In this study, we developed a non-enzymatic photoelectrochemical sensor using a BiOBr-CuO (BiCu) electrode, which was synthesized via solvothermal method. The sensor was designed for the simultaneous detection of glucose and tetracycline. Our study revealed that the BiCu electrode exhibited superior photocurrent generation compared to the individual BiOBr and CuO electrodes, as demonstrated by cyclic voltammetry and amperometric studies. The BiCu electrode's performance has increased due to the formation of a heterojunction between CuO and BiOBr, which modifies the UV–visible DRS spectrum and generates an internal electric field that reduces the recombination of the photogenerated carriers. This enhanced the capability of the sensor to detect both glucose and tetracycline. We successfully applied the proposed photoelectrochemical sensor to detect human blood glucose level. The sensitivity and detection limit for glucose and tetracycline are 0.1342 mAmM−1cm−2, 0.014 mM and 1.7234 mAmM−1cm−2, 2.0 μM respectively. Thus, the fabricated electrode demonstrated exceptional catalytic activity, high selectivity, good reproducibility, wide linear detection range, low limit of detection,long-term stability, ease of synthesis, good stability and notable selectivity for detecting both glucose and tetracycline This suggests that the BiCu electrode has significant potential as a reliable platform for the detection of glucose and tetracycline.
{"title":"Fabrication of a non-enzymatic photoelectrochemical sensor based on a BiOBr-CuO nanocomposite for detecting Glucose and Tetracycline","authors":"AnnieCanisius D , Joselene Suzan Jennifer P , Joe Raja Ruban M , Davis Varghese , Gladys Joysi M , Muthupandi S , Madhavan J , Victor Antony Raj M , Saravanan Muthupandian","doi":"10.1016/j.sintl.2024.100310","DOIUrl":"10.1016/j.sintl.2024.100310","url":null,"abstract":"<div><div>In this study, we developed a non-enzymatic photoelectrochemical sensor using a BiOBr-CuO (BiCu) electrode, which was synthesized via solvothermal method. The sensor was designed for the simultaneous detection of glucose and tetracycline. Our study revealed that the BiCu electrode exhibited superior photocurrent generation compared to the individual BiOBr and CuO electrodes, as demonstrated by cyclic voltammetry and amperometric studies. The BiCu electrode's performance has increased due to the formation of a heterojunction between CuO and BiOBr, which modifies the UV–visible DRS spectrum and generates an internal electric field that reduces the recombination of the photogenerated carriers. This enhanced the capability of the sensor to detect both glucose and tetracycline. We successfully applied the proposed photoelectrochemical sensor to detect human blood glucose level. The sensitivity and detection limit for glucose and tetracycline are 0.1342 mAmM<sup>−1</sup>cm<sup>−2</sup>, 0.014 mM and 1.7234 mAmM<sup>−1</sup>cm<sup>−2</sup>, 2.0 μM respectively. Thus, the fabricated electrode demonstrated exceptional catalytic activity, high selectivity, good reproducibility, wide linear detection range, low limit of detection,long-term stability, ease of synthesis, good stability and notable selectivity for detecting both glucose and tetracycline This suggests that the BiCu electrode has significant potential as a reliable platform for the detection of glucose and tetracycline.</div></div>","PeriodicalId":21733,"journal":{"name":"Sensors International","volume":"6 ","pages":"Article 100310"},"PeriodicalIF":0.0,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142704508","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-13DOI: 10.1016/j.sintl.2024.100309
Salvatore A. Pullano , Giuseppe Oliva , Pierangela Presta , Nazareno Carullo , Michela Musolino , Michele Andreucci , Davide Bolignano , Antonino S. Fiorillo , Giuseppe Coppolino
Hemodialysis is the primary treatment for patients with total loss of renal function and is performed through a vascular access called an arteriovenous fistula (AVF). AVF can be associated with several complications, such as stenosis, thrombosis, and aneurysms. While digital subtraction angiography (DSA) is the gold standard for AVF monitoring, its limited availability, invasiveness, and harmfulness has enabled Doppler ultrasound (DUS) as alternative technique. Herein, the development of a portable device based on a triboelectric sensor for AVF monitoring that exploits the concept of impedance cardiography (ICG) is presented. The triboelectric sensor consists of a thin polyvinylidene fluoride (PVDF) layer placed close to the AVF to evaluate the triboelectric ICG signal (T-ICG), thus avoiding the need for standard multiple-electrode equipment. Electrocardiographic (ECG) dry electrodes based on a composite of polydimethylsiloxane (PDMS) and multi-walled carbon nanotubes (MWCNTs) were fabricated. Concept validation was performed in a cohort of hemodialysis patients with and without AVF stenosis. The results demonstrated a linear dependence between blood flow and the maximum deviation (dZ/dtmax) of the T-ICG pattern. Patients with stenosis showed a statistically significant change in morphology at the B-point. The extent of stenosis was evaluated by analyzing the temporal slope of the ICG pattern in the B- and C-point regions, evidencing a linear trend for stenosis from 20 % up to 60 %. The proposed device represents an innovative approach compared with the gold clinical standards for the continuous monitoring of AVF in hemodialysis patients.
血液透析是治疗完全丧失肾功能患者的主要方法,通过一种叫做动静脉瘘(AVF)的血管通路进行。动静脉瘘可能伴有多种并发症,如狭窄、血栓和动脉瘤。虽然数字减影血管造影术(DSA)是监测动静脉瘘的黄金标准,但由于其有限性、侵入性和有害性,多普勒超声(DUS)已成为替代技术。本文介绍了利用阻抗心动图(ICG)概念开发的用于动静脉瘘监测的基于三电传感器的便携式设备。三电传感器由靠近动静脉导管的聚偏二氟乙烯(PVDF)薄层组成,用于评估三电 ICG 信号(T-ICG),从而避免了使用标准的多电极设备。基于聚二甲基硅氧烷(PDMS)和多壁碳纳米管(MWCNTs)复合材料的心电图(ECG)干电极已制作完成。在一组有和没有动静脉瘘狭窄的血液透析患者中进行了概念验证。结果表明,血流量与 T-ICG 模式的最大偏差(dZ/dtmax)呈线性关系。有狭窄的患者在 B 点的形态变化具有统计学意义。通过分析 B 点和 C 点区域 ICG 图形的时间斜率,可以评估血管狭窄的程度。与连续监测血液透析患者动静脉瘘的黄金临床标准相比,该设备是一种创新方法。
{"title":"A portable easy-to-use triboelectric sensor for arteriovenous fistula monitoring in dialysis patients","authors":"Salvatore A. Pullano , Giuseppe Oliva , Pierangela Presta , Nazareno Carullo , Michela Musolino , Michele Andreucci , Davide Bolignano , Antonino S. Fiorillo , Giuseppe Coppolino","doi":"10.1016/j.sintl.2024.100309","DOIUrl":"10.1016/j.sintl.2024.100309","url":null,"abstract":"<div><div>Hemodialysis is the primary treatment for patients with total loss of renal function and is performed through a vascular access called an arteriovenous fistula (AVF). AVF can be associated with several complications, such as stenosis, thrombosis, and aneurysms. While digital subtraction angiography (DSA) is the gold standard for AVF monitoring, its limited availability, invasiveness, and harmfulness has enabled Doppler ultrasound (DUS) as alternative technique. Herein, the development of a portable device based on a triboelectric sensor for AVF monitoring that exploits the concept of impedance cardiography (ICG) is presented. The triboelectric sensor consists of a thin polyvinylidene fluoride (PVDF) layer placed close to the AVF to evaluate the triboelectric ICG signal (T-ICG), thus avoiding the need for standard multiple-electrode equipment. Electrocardiographic (ECG) dry electrodes based on a composite of polydimethylsiloxane (PDMS) and multi-walled carbon nanotubes (MWCNTs) were fabricated. Concept validation was performed in a cohort of hemodialysis patients with and without AVF stenosis. The results demonstrated a linear dependence between blood flow and the maximum deviation (dZ/dt<sub>max</sub>) of the T-ICG pattern. Patients with stenosis showed a statistically significant change in morphology at the B-point. The extent of stenosis was evaluated by analyzing the temporal slope of the ICG pattern in the B- and C-point regions, evidencing a linear trend for stenosis from 20 % up to 60 %. The proposed device represents an innovative approach compared with the gold clinical standards for the continuous monitoring of AVF in hemodialysis patients.</div></div>","PeriodicalId":21733,"journal":{"name":"Sensors International","volume":"6 ","pages":"Article 100309"},"PeriodicalIF":0.0,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142653384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-12DOI: 10.1016/j.sintl.2024.100308
M.N. Somashekar , M. Dhanalakshmi , T.S. Nagamani , T. Subhas Chandra , T.M. Sharanakumar , C.R. Ravikumar
In the present work, a novel fuel made from the leaves of the Gotu kola (Centella Asiatica) plant is used to produce calcium oxide nanoparticles (CaO NPs) in an eco-friendly manner. The results of the PXRD experiments, the average crystallite size for CaO NPs is 38 nm, which is consistent with the findings of the TEM. As per DRS investigation, the energy gap of CaONPs is 3.253 eV. Fast Blue (FB) and Fast Orange (FO) dye photodegradation was effectively enhanced by the plant-mediated CaO NPs under UV-light irradiation, showing high efficiency within 120 min. The CaO demonstrated remarkable photodegradation process against the FO and FB dyes under UV light, with rates of 79.52 % and 61.43 % after 120 min. CaO NPs' electrochemical characteristics were ascertained using a carbon paste electrode (CPE) dipped in a 0.1N HCl solution. In cyclic voltammetry evaluation, the green CaO NPs showed greater sensitivity at various scan rates. Ascorbic acid and uric acid were finally shown to have exceptional redox reaction and ascorbic acid and uric acid detection capabilities when they were used as analytes.
本研究利用积雪草叶制成的新型燃料,以环保的方式生产氧化钙纳米粒子(CaO NPs)。PXRD 实验结果表明,CaO NPs 的平均结晶尺寸为 38 nm,这与 TEM 的结果一致。根据 DRS 调查,CaONPs 的能隙为 3.253 eV。在紫外光照射下,植物介导的 CaO NPs 有效地增强了快蓝(FB)和快橙(FO)染料的光降解,在 120 分钟内显示出很高的效率。在紫外光下,CaO 对 FO 和 FB 染料的光降解效果显著,120 分钟后的降解率分别为 79.52% 和 61.43%。使用浸在 0.1N HCl 溶液中的碳浆电极(CPE)确定了 CaO NPs 的电化学特性。在循环伏安法评估中,绿色 CaO NPs 在各种扫描速率下都表现出更高的灵敏度。抗坏血酸和尿酸最终被证明具有优异的氧化还原反应以及抗坏血酸和尿酸检测能力。
{"title":"Photocatalytic and electrochemical sensor detection of ascorbic and uric acid using novel plant extract green synthesis of CaO nanoparticles","authors":"M.N. Somashekar , M. Dhanalakshmi , T.S. Nagamani , T. Subhas Chandra , T.M. Sharanakumar , C.R. Ravikumar","doi":"10.1016/j.sintl.2024.100308","DOIUrl":"10.1016/j.sintl.2024.100308","url":null,"abstract":"<div><div>In the present work, a novel fuel made from the leaves of the Gotu kola (Centella Asiatica) plant is used to produce calcium oxide nanoparticles (CaO NPs) in an eco-friendly manner. The results of the PXRD experiments, the average crystallite size for CaO NPs is 38 nm, which is consistent with the findings of the TEM. As per DRS investigation, the energy gap of CaONPs is 3.253 eV. Fast Blue (FB) and Fast Orange (FO) dye photodegradation was effectively enhanced by the plant-mediated CaO NPs under UV-light irradiation, showing high efficiency within 120 min. The CaO demonstrated remarkable photodegradation process against the FO and FB dyes under UV light, with rates of 79.52 % and 61.43 % after 120 min. CaO NPs' electrochemical characteristics were ascertained using a carbon paste electrode (CPE) dipped in a 0.1N HCl solution. In cyclic voltammetry evaluation, the green CaO NPs showed greater sensitivity at various scan rates. Ascorbic acid and uric acid were finally shown to have exceptional redox reaction and ascorbic acid and uric acid detection capabilities when they were used as analytes.</div></div>","PeriodicalId":21733,"journal":{"name":"Sensors International","volume":"6 ","pages":"Article 100308"},"PeriodicalIF":0.0,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142704505","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Current global warming and climate change under the greenhouse effect call for a thorough understanding of the spatial distribution of greenhouse gases in different atmospheric layers. Lidar systems are the most effective for remote greenhouse gas monitoring. We design a two-channel infrared OPO lidar optical system for remote DIAL/DOAS sensing of carbon dioxide and water vapor in the atmosphere. In this work, optimal geometric parameters of the transceiving channel of the lidar optical system are chosen, a need to focus laser radiation at a distance of 1 km from an observation point is demonstrated, and numerical simulations confirm the possibility of detecting lidar signals ranging from 10−7 to 10−10 W in the informative spectral range 4800–5100 cm−1 (1960–2083 nm). Laboratory experiments with the main components of the lidar system with experimentally confirmed parameters, which simulate atmospheric measurements of CO2 absorption at a calibrated sensing wavelength of 2005 nm (4987 cm−1) (pressure of 1 atm; CO2 concentration corresponding to the midlatitude summer background atmosphere) in the informative spectral range of the lidar system, enable selecting a pair of wavelengths with resonant absorption of the target gas near 2005 nm to study the background state of the atmosphere in the surface layer. Efficiency of the lidar optical system is confirmed by in situ test experiments, where backscattering signals from a topographic target with an albedo of ∼0.15 spaced 168 m apart from an observer are recorded at 60 mV when operating along a horizontal atmospheric path. The lidar system we design can be used in measuring complexes at carbon test sites. It can also be used for atmospheric monitoring in industrial centers, at background measuring stations, and in swamp areas.
{"title":"Dual-channel infrared OPO lidar optical system for remote sensing of greenhouse gases in the atmosphere: Design and characteristics","authors":"S.A. Sadovnikov, S.V. Yakovlev, N.S. Kravtsova, O.A. Romanovskii, D.A. Tuzhilkin","doi":"10.1016/j.sintl.2024.100307","DOIUrl":"10.1016/j.sintl.2024.100307","url":null,"abstract":"<div><div>Current global warming and climate change under the greenhouse effect call for a thorough understanding of the spatial distribution of greenhouse gases in different atmospheric layers. Lidar systems are the most effective for remote greenhouse gas monitoring. We design a two-channel infrared OPO lidar optical system for remote DIAL/DOAS sensing of carbon dioxide and water vapor in the atmosphere. In this work, optimal geometric parameters of the transceiving channel of the lidar optical system are chosen, a need to focus laser radiation at a distance of 1 km from an observation point is demonstrated, and numerical simulations confirm the possibility of detecting lidar signals ranging from 10<sup>−7</sup> to 10<sup>−10</sup> W in the informative spectral range 4800–5100 cm<sup>−1</sup> (1960–2083 nm). Laboratory experiments with the main components of the lidar system with experimentally confirmed parameters, which simulate atmospheric measurements of CO<sub>2</sub> absorption at a calibrated sensing wavelength of 2005 nm (4987 cm<sup>−1</sup>) (pressure of 1 atm; CO<sub>2</sub> concentration corresponding to the midlatitude summer background atmosphere) in the informative spectral range of the lidar system, enable selecting a pair of wavelengths with resonant absorption of the target gas near 2005 nm to study the background state of the atmosphere in the surface layer. Efficiency of the lidar optical system is confirmed by in situ test experiments, where backscattering signals from a topographic target with an albedo of ∼0.15 spaced 168 m apart from an observer are recorded at 60 mV when operating along a horizontal atmospheric path. The lidar system we design can be used in measuring complexes at carbon test sites. It can also be used for atmospheric monitoring in industrial centers, at background measuring stations, and in swamp areas.</div></div>","PeriodicalId":21733,"journal":{"name":"Sensors International","volume":"6 ","pages":"Article 100307"},"PeriodicalIF":0.0,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142653383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The paper demonstrates the effectiveness of using numerical simulation to select parameters of the system for monitoring the deformation behavior of structures. Consideration is given to a bolted flange connection with a gasket, the performance of which is determined by the level of bolt tightening. Bolt tension control technique is based on the strain measurement with fiber optic sensors embedded in the gasket. The results of numerical modeling of deformation for different variants of bolt tensioning are discussed. Strain measurement in the gasket by means of distributed fiber-optic sensors on the basis of Rayleigh scattering is carried out taking into account the results of numerical simulation. Another type of fiber optic sensors that is based on the Bragg gratings is used to implement additional control of the results of measurement. An algorithm to realize strain measurement by two types of sensors located on the same optic fiber is proposed. The results of experimental strain measurements demonstrate that fiber optic sensors can be used to detect changes in bolt tensioning, which can cause failure of a flange joint.
{"title":"Flange joint monitoring based on strain measurement with fiber optic sensors embedded in gaskets","authors":"Valerii Matveenko, Andrey Fedorov, Grigorii Serovaev, Elizaveta Galkina, Elizaveta Vindokurova","doi":"10.1016/j.sintl.2024.100306","DOIUrl":"10.1016/j.sintl.2024.100306","url":null,"abstract":"<div><div>The paper demonstrates the effectiveness of using numerical simulation to select parameters of the system for monitoring the deformation behavior of structures. Consideration is given to a bolted flange connection with a gasket, the performance of which is determined by the level of bolt tightening. Bolt tension control technique is based on the strain measurement with fiber optic sensors embedded in the gasket. The results of numerical modeling of deformation for different variants of bolt tensioning are discussed. Strain measurement in the gasket by means of distributed fiber-optic sensors on the basis of Rayleigh scattering is carried out taking into account the results of numerical simulation. Another type of fiber optic sensors that is based on the Bragg gratings is used to implement additional control of the results of measurement. An algorithm to realize strain measurement by two types of sensors located on the same optic fiber is proposed. The results of experimental strain measurements demonstrate that fiber optic sensors can be used to detect changes in bolt tensioning, which can cause failure of a flange joint.</div></div>","PeriodicalId":21733,"journal":{"name":"Sensors International","volume":"6 ","pages":"Article 100306"},"PeriodicalIF":0.0,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142653385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}