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1.
Artículo en Inglés | MEDLINE | ID: mdl-38587943

RESUMEN

Microbial Fuel Cells (MFCs) have recently gained attention, as they are inexpensive, green in nature, and sustainable. As per the report, by Allied Market Research the global market size of MFCs will increase from $264.8 million in 2021 to $452.2 million in 2030, growing at a CAGR of 4.5%. The present work is a comparative study of various types of electrolytes that can be used in MFCs. The working electrodes were printed using conducting graphene-based Polylactic Acid (PLA) filaments with the help of a 3D printer under the principle of the fused deposition method. Simulated electrolytes and natural environmental microbial electrolytes were used here. Also, electrolytes of pure E. coli culture were studied. Lake water reported the highest power density of 8.259 mW/cm2 while Stale E. Coli reported the lowest around 0.184 mW/cm2. The study comprehensively lists potential wastewaters that can fuel the MFCs. With the pioneering of various comparative studies of electrolytes, one can insight into the recruitment of electrolytes with high-performance benchmarks for miniaturized energy storage and other microelectronics applications.

2.
Anal Methods ; 16(17): 2643-2653, 2024 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-38624187

RESUMEN

A pair of pyrene-based chalcogen derivatives have been developed, which demonstrate multimodal ratiometric response towards hydrazine. Although these probes share a common pyrene core and differ primarily in the electronic nature of their terminal side arms, they display distinct photophysical properties. Notably, both probes undergo significant spectral changes upon the addition of hydrazine, but probe 1 exhibits a more pronounced interaction (∼5-fold fluorescence enhancement) than probe 2, attributed to the higher level of aggregation in probe 2, rendering the binding site less accessible to the incoming analyte. Additionally, we have explored electrochemical techniques, including cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), for hydrazine detection. Our molecular design strategy relies on ratiometric-responsive specific cyclization triggered by hydrazine, leading to the disruption of the π-conjugated system and the subsequent suppression of intramolecular charge transfer (ICT) processes, along with dis-assembly of the aggregated probe molecules. These probes enable the nakеd-eye detection of hydrazine, with a low detection limit of 7.33 ppb and 7.58 ppb for probe 1 and 2, respectively. Furthermore, we have investigated cost-effective probe-coatеd paper strips for the detection of hydrazine in water.

3.
Artículo en Inglés | MEDLINE | ID: mdl-38507383

RESUMEN

L-Tyrosine (L-Tyr), a critical amino acid whose aberrant levels impact melanin and dopamine levels in human body while also increasing insulin resistance thereby increasing the risk of type 2. The objective of this study was to detect the amount of L-Tyr in human fluids by tailored electrochemical synthesis of well adhered, homogenous and thin molecularly imprinted polymers (MIPs) by the electro-polymerization of pyrrole on glassy carbon electrode modified functionalized multi-walled carbon nanotubes. The key benefits of this procedure over previous imprinting techniques were the elimination of expensive materials like Au and tedious multi-step synthesis, for L-Tyr detection using a handheld potentiostat. The developed particles were characterized using Fourier Transform Infrared Spectroscopy, Scanning Electron Microscope, Chronoamperometry, and Cyclic Voltammetry. With strong reproducibility and stability, this optimized approach provides a rapid and effective method of preparing and sensing MIPs for the target analyte with a broad linear range of 1 µM to 2000 µM. The Limit of Detection and Limit of Quantification were 0.4 µM and 1.47 µM, respectively. The engineered sensor was validated for quantifying the concentrations of L-Tyr in human blood and serum samples, yielding satisfactory recovery and can be expanded in future to detect analytes simultaneous.

4.
Sensors (Basel) ; 23(23)2023 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-38067687

RESUMEN

Antimicrobial resistance (AMR) is a global health threat, progressively emerging as a significant public health issue. Therefore, an antibiotic susceptibility study is a powerful method for combating antimicrobial resistance. Antibiotic susceptibility study collectively helps in evaluating both genotypic and phenotypic resistance. However, current traditional antibiotic susceptibility study methods are time-consuming, laborious, and expensive. Hence, there is a pressing need to develop simple, rapid, miniature, and affordable devices to prevent antimicrobial resistance. Herein, a miniaturized, user-friendly device for the electrochemical antibiotic susceptibility study of Escherichia coli (E. coli) has been developed. In contrast to the traditional methods, the designed device has the rapid sensing ability to screen different antibiotics simultaneously, reducing the overall time of diagnosis. Screen-printed electrodes with integrated miniaturized reservoirs with a thermostat were developed. The designed device proffers simultaneous incubator-free culturing and detects antibiotic susceptibility within 6 h, seven times faster than the conventional method. Four antibiotics, namely amoxicillin-clavulanic acid, ciprofloxacin, ofloxacin, and cefpodoxime, were tested against E. coli. Tap water and synthetic urine samples were also tested for antibiotic susceptibility. The results show that the device could be used for antibiotic resistance susceptibility testing against E. coli with four antibiotics within six hours. The developed rapid, low-cost, user-friendly device will aid in antibiotic screening applications, enable the patient to receive the appropriate treatment, and help to lower the risk of anti-microbial resistance.


Asunto(s)
Infecciones por Escherichia coli , Escherichia coli , Humanos , Pruebas de Sensibilidad Microbiana , Antibacterianos/farmacología , Combinación Amoxicilina-Clavulanato de Potasio
5.
ACS Omega ; 8(43): 40836-40847, 2023 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-37929146

RESUMEN

Currently, very few dicyano and tetracyanoquinodimethane (TCNQ) based molecules are utilized as active layers, sandwiched between the electron and hole transport layer in organic solar cell (OSC) devices. Nevertheless, simple mono- and disubstituted TCNQ derivatives as exclusively active layers are yet unexplored and provide scope for further investigation. In this study, TCNQ derivatives with varying amine substituents, namely, AEPYDQ (1), BMEDDQ (2), MATBTCNQ (3), and MITATCNQ (4), were explored as efficient standalone, flexible, all small molecule OSC devices. Particularly, 1 resulted in the highest device efficiency of 11.75% with an aromatic amine, while 2 possessing an aliphatic amine showed the lowest power conversion efficiency (PCE; 2.12%). Notably, the short circuit current density (JSC) of device 1 increased from 2 mA/cm2 in the dark to 9.12 mA/cm2 under light, indicating a significant boost in the current generation. Further, 1 manifested more crystallinity than others. Interestingly, 4 exhibited a higher PCE (5.90%) than 3 (PCE is 2.58%), though 3 is disubstituted with an aromatic amine, probably attributed to the electron-withdrawing effects of the -CF3 and -CN groups in 3 reducing the available π-electron density for stacking. Therefore, this study emphasizes crystallinity, significantly on the PCE, offering insights into the design of many such efficient OSCs.

6.
Biosens Bioelectron ; 238: 115582, 2023 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-37572409

RESUMEN

The sensitive and accurate detection of glucose and lactate is essential for early diagnosis and effective management of diabetes complications. Herein, a 3D Printed ECL imaging system integrated with a Smartphone has been demonstrated to advance the traditional ECL to make a portable, affordable, and turnkey point-of-care solution to detect various human metabolites. A universal cross-platform application was introduced for analyzing ECL emitted signals to automate the whole detection process for real-time monitoring and rapid diagnostics. The developed ECL system was successfully applied and validated for detecting glucose and lactate using a single-electrode ECL biosensing platform. For glucose and lactate detection, the device showed a linear range from 0.1 mM to 1 mM and 0.1 mM-4 mM with a detection limit (LoD) of 0.04 mM and 0.1 mM, and a quantification limit (LoQ) of 0.142 mM and 0.342 mM, respectively. The developed method was evaluated for device stability, accuracy, interference, and real sample analysis. Furthermore, to assist in selecting the accurate and economic ECL sensing platform, SE-ECL devices fabricated via different fabrication approaches such as Laser-Induced Graphene, Screen Printing, and 3D Printing are studied for the conductivity of electrode and its significance on ECL signal. It was observed that emitted ECL signal is independent of the electrical conductivity for the same concentration of analytes. The findings suggested that the developed miniaturized point-of-care ECL platform would be a comprehensive and integrated solution for detecting other human metabolites and have the potential to be used in clinical applications.


Asunto(s)
Técnicas Biosensibles , Mediciones Luminiscentes , Humanos , Mediciones Luminiscentes/métodos , Teléfono Inteligente , Técnicas Biosensibles/métodos , Ácido Láctico/análisis , Técnicas Electroquímicas/métodos , Glucosa , Aprendizaje Automático
7.
Materials (Basel) ; 16(14)2023 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-37512303

RESUMEN

In this work, we study the effects of treating nanostructured SnO2-SiO2 films derived by a sol-gel method with nitrogen and oxygen plasma. The structural and chemical properties of the films are closely investigated. To quantify surface site activity in the films following treatment, we employed a photocatalytic UV degradation test with brilliant green. Using X-ray photoelectron spectroscopy, it was found that treatment with oxygen plasma led to a high deviation in the stoichiometry of the SnO2 surface and even the appearance of a tin monoxide phase. These samples also exhibited a maximum photocatalytic activity. In contrast, treatment with nitrogen plasma did not lead to any noticeable changes in the material. However, increasing the power of the plasma source from 250 W to 500 W led to the appearance of an SnO fraction on the surface and a reduction in the photocatalytic activity. In general, all the types of plasma treatment tested led to amorphization in the SnO2-SiO2 samples.

8.
Int J Biol Macromol ; 245: 125502, 2023 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-37348592

RESUMEN

Futuristic microfluidics will require alternative ways to extend its potential in vast areas by integrating various facets such as automation of different subsystems, multiplexing, incorporation of cyber-physical capabilities, and rapid prototyping. On the rapid prototyping aspect, for the last decade, additive manufacturing (AM) or 3D printing (3DP) has advanced to become an alternative fabrication process for microfluidic devices, enabling industry-level abilities towards mass production. In this context, for the first time, this work demonstrates the fabrication of monolithic multilayer microfluidic devices (MMMD) from planar orientation (1 layer) to nonplanar (4 layers) monolithic microchannels. The developed MMM device was impeccable for synthesizing highly potentialized silver nanoparticles (AgNPs) in <1 s. Moreover, the transport of chemical species with laminar flow simulations was performed on the process along with the thorough characterizations of produced AgNPs, finding the mean AgNPs particle size of around 35 nm without any post-processing requirements. The well-known catalytic activity of AgNPs was leveraged to enhance weak chemiluminescence (CL) sensing signals by >1300 %, increasing CL sensitivity. Further, machine learning (ML) predictive models encouraged to obtain the experimental parameters without human intervention iterations for target-specific applications. The proposed methodology finds the potential to save resources, time, and enables automation with rapid prototyping, providing possibilities for mass fabrications.


Asunto(s)
Nanopartículas del Metal , Microfluídica , Humanos , Microfluídica/métodos , Plata , Luminiscencia , Impresión Tridimensional
9.
STAR Protoc ; 4(2): 102327, 2023 May 25.
Artículo en Inglés | MEDLINE | ID: mdl-37243603

RESUMEN

Here, we present a protocol for a miniaturized microfluidic device that enables quantitative tracking of bacterial growth. We describe steps for fabricating a screen-printed electrode, a laser-induced graphene heater, and a microfluidic device with its integrations. We then detail the electrochemical detection of bacteria using a microfluidic fuel cell. The laser-induced graphene heater provides the temperature for the bacterial culture, and metabolic activity is recognized using a bacterial fuel cell. Please see Srikanth et al.1 for comprehensive information on the application and execution of this protocol.

10.
Nanotechnology ; 34(29)2023 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-37129108

RESUMEN

Recent progress in thein situsynthesise of various nanomaterials has gained tremendous interest and wide applications in various fields. For the first time to the best of our knowledge, this work reports a methodology of ultra-fastin situsynthesis of cobalt-cobalt oxide-reduced graphene oxide (Co-Co3O4-rGO (CC-rGO)) composite by laser ablation. The photothermal reduction technique was leveraged to develop the CC-rGO. For this, a low-cost 450 nm blue diode laser was irradiated onto a grade 1 filter paper in the presence of cobalt ions readily patterns the carbon matrix of paper to the composite material. Moreover, the variation of cobalt concentrations from 0.1-0.5 M led to structural and morphological changes. Standard techniques were adopted for thorough characterizations of developed sensor material for conductivity analysis, specific surface area, crystal-structural information, surface morphology, and chemical composition. The observed results were highly promoting towards the electrochemical sensing applications. Further, the developed sensor was found to be highly selective toward detecting a vital bio analyte alkaline phosphatase (ALP). The sensors performance was highly significant in the linear range of 10-800 mU l-1with a detection limit of 10.13 mU l-1. The sensors applicability was further validated in actual human serum samples via a recovery-based approach. In the future, the developedin situmaterial methodology can begin a rapid composite material synthesis at a larger scale.


Asunto(s)
Técnicas Biosensibles , Grafito , Nanocompuestos , Humanos , Fosfatasa Alcalina , Grafito/química , Cobalto/química , Nanocompuestos/química , Colorantes , Técnicas Biosensibles/métodos , Rayos Láser , Técnicas Electroquímicas/métodos
11.
Biotechniques ; 74(4): 158-171, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-37139914

RESUMEN

The recent cases of COVID-19 have brought the prospect of and requirement for point-of-care diagnostic devices into the limelight. Despite all the advances in point-of-care devices, there is still a huge requirement for a rapid, accurate, easy-to-use, low-cost, field-deployable and miniaturized PCR assay device to amplify and detect genetic material. This work aims to develop an Internet-of-Things automated, integrated, miniaturized and cost-effective microfluidic continuous flow-based PCR device capable of on-site detection. As a proof of application, the 594-bp GAPDH gene was successfully amplified and detected on a single system. The presented mini thermal platform with an integrated microfluidic device has the potential to be used for the detection of several infectious diseases.


Asunto(s)
COVID-19 , Humanos , COVID-19/diagnóstico , Técnicas de Amplificación de Ácido Nucleico , Reacción en Cadena de la Polimerasa , Dispositivos Laboratorio en un Chip , ADN
12.
ACS Sens ; 8(4): 1373-1390, 2023 04 28.
Artículo en Inglés | MEDLINE | ID: mdl-37074840

RESUMEN

Presently, numerous state-of-the-art approaches are being adapted for gas sensing and monitoring. These include hazardous gas leak detection as well as ambient air monitoring. Photoionization detectors, electrochemical sensors, and optical infrared sensors are a few of the commonly widely used technologies. Extensive reviews on the current state of gas sensors have been summarized. These sensors, which are either nonselective or semiselective, are affected by unwanted analytes. On the other hand, volatile organic compounds (VOCs) can be heavily mixed in many vapor intrusion situations. To determine the individual VOCs in a highly mixed gas sample using nonselective or semiselective gas sensors, gas separation and discrimination technologies are highly warranted. These technologies include gas permeable membranes, metal-organic frameworks, microfluidics and IR bandpass filters for different sensors, respectively. The majority of these gas separation and discrimination technologies are currently being developed and evaluated in laboratory-controlled environments and have not yet been extensively utilized in the field for vapor intrusion monitoring. These technologies show promise for continued development and application in the field for more complex gas mixtures. Hence, the present review focuses on the perspectives and a summary of the existing gas separation and discrimination technologies for the currently popular reported gas sensors in environmental applications.


Asunto(s)
Gases , Compuestos Orgánicos Volátiles
13.
IEEE Trans Nanobioscience ; 22(4): 881-888, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37022373

RESUMEN

This work delves upon developing a two-layer plasma-bonded microfluidic device with a microchannel layer and electrodes for electroanalytical detection of heavy metal ions. The three-electrode system was realized on an ITO-glass slide by suitably etching the ITO layer with the help of CO2 laser. The microchannel layer was fabricated using a PDMS soft-lithography method wherein the mold created by maskless lithography. The optimized dimensions opted to develop a microfluidic device with length of 20 mm, width of 0.5 mm and gap of 1 mm. The device, with bare unmodified ITO electrodes, was tested to detect Cu and Hg by a portable potentiostat connected with a smartphone. The analytes were introduced in the microfluidic device with a peristaltic pump at an optimal flow rate of [Formula: see text]/min. The device exhibited sensitive electro-catalytic sensing of both the metals by achieving an oxidation peak at -0.4 V and 0.1 V for Cu and Hg respectively. Furthermore, square wave voltammetry (SWV) approach was used to analyze the scan rate effect and concentration effect. The device also used to simultaneously detect both the analytes. During simultaneous sensing of Hg and Cu, the linear range was observed between [Formula: see text] to [Formula: see text], the limit of detection (LOD) was found to be [Formula: see text] and [Formula: see text] for Cu and Hg respectively. Further, no interference with other co-existing metal ions was found manifesting the specificity of the device to Cu and Hg. Finally, the device was successfully tested with real samples like tap water, lake water, and serum with remarkable recovery percentages. Such portable devices pave way for detecting various heavy metal ions in a point-of-care environment. The developed device can also be used for detection of other heavy metals like cadmium, lead, zinc etc., by modifying the working electrode with the various nanocomposites.


Asunto(s)
Mercurio , Metales Pesados , Cobre , Sistemas de Atención de Punto , Electrodos , Agua , Dispositivos Laboratorio en un Chip
14.
Environ Res ; 220: 115192, 2023 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-36587721

RESUMEN

This work demonstrates the simultaneous identification of four hazardous heavy metals in water samples, namely copper, lead, cadmium, and mercury. A simple yet selective electrode with the simplest fabrication procedure was used. The modified porous carbon threads coated with gold nanoparticles (AuNPs) was employed as a working electrode. The surface chemistry and morphology of the AuNPs deposited porous carbon thread surface were examined. The electrocatalytic activity of the metals on the Au-modified thread surface was observed using the differential pulse voltammetry (DPV) technique. Furthermore, all four metal ions were detected simultaneously, and no interference was observed. Individual and simultaneous experiments to test the impact of concentration revealed that the limit of detection (LoD) was observed to be 1.126 µM, 1.419 µM, 0.966 µM, 0.736 µM for the Cd2+, Pb2+, Cu2+, and Hg2+ metal ions respectively in a linear concentration range of 10-110 µM of each. Subsequently, the study of pH, interference with coexisting metal ions, repeatability study, and stability analysis was also performed. A real sample analysis utilising three different lake water samples is also carried out to further understand the application of the proposed sensor. A good recovery rate is achieved, and the results are reported. This work paves way for the on-field applicability of the present heavy metal detection platform.


Asunto(s)
Mercurio , Nanopartículas del Metal , Metales Pesados , Oro , Microelectrodos , Fibra de Carbono , Porosidad , Metales Pesados/análisis , Mercurio/análisis , Carbono , Agua , Iones
15.
Anal Chim Acta ; 1237: 340591, 2023 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-36442949

RESUMEN

Bacterial contamination and infection is a major health concern today leading to the significance of its detection. Being lab-based bacterial culturing processes, the present approaches are time consuming and require trained skillset. An economical, and miniaturized lab-on-chip device, capable of simultaneous detection of bacterial growth, could be a benchmarking tool for monitoring the bacterial contamination. Herein, the microfluidic-based electrochemical device for a fast, susceptible, detection of Escherichia coli was developed. The device could aid incubator free bacteria culturing in the ambient atmosphere and simultaneously monitor and detect the growth electrochemically. A three-electrode system, integrated with a reservoir and a portable thermostat temperature controller was fabricated and assembled. To achieve this, three-electrodes were embedded on the microfluidic device by screen-printing carbon paste, and the working electrode was enhanced by graphitized mesoporous carbon. Cyclic voltammetry response was noted as the function of concentration and growth of Escherichia Coli in the reservoir. The device gave a linear bacterial concentration range of 0.336 × 1012 to 40 × 1012 CFU mL-1, detection limit of 0.35 CFU mL-1 and the quantification limit of 1.05 CFU mL-1 which was less than the maximum allowable limit. The developed platform was further used to detect and continuously monitor the bacterial growth in the real sample (mango juice) for a period of 36 h. Finally, the interference from other common bacteria on the electrode selectivity was also investigated. Such approach in being further modified for specific sensing of bacteria in patients suffering from different diseases such as corneal ulcers, Diarrhea, tuberculosis, leprosy, and syphilis.


Asunto(s)
Infecciones por Escherichia coli , Escherichia coli , Humanos , Dispositivos Laboratorio en un Chip , Microfluídica , Carbono
16.
IEEE Trans Nanobioscience ; 22(2): 337-344, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-35820008

RESUMEN

This work delves upon the development of different types of miniaturized and 3D printed devices having interdigitated electrodes (IDEs) for the detection of Escherichia coli (E. coli) bacteria. The IDEs were fabricated using different approaches including laser-induced graphene (LIG) on polyamide, direct laser writing on glass, and polymeric 3D printing technique, and their suitability for bacteria detection has been compared. The electrochemical impedance spectroscopy (EIS) technique was employed to detect the E. coli bacteria in the prepared miniaturized devices, and the sensory response was compared. EIS was performed in the frequency range between 1 Hz to 1 MHz to record the bacterial growth and activities as a function of change in electrical impedance, and detection performance of the different miniaturized devices with IDEs were compared. It was observed that the LIG-based IDE sensor provided better sensitivity compared to that of the other two approaches. The obtained results indicate that the magnitude of impedance changes by around 2.5 [Formula: see text] per doubling of E.coli cells. With fast and flexible fabrication process capabilities, such microdevices may be used as suitable IDE sensors for microscale pathogenic detection for biomedical and clinical analysis.


Asunto(s)
Técnicas Biosensibles , Escherichia coli , Electrodos , Polímeros , Impedancia Eléctrica
17.
IEEE Trans Nanobioscience ; 22(3): 548-553, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-36269916

RESUMEN

Metabolic biomarkers, such as Dopamine (DA), Uric acid (UA), and Ascorbic acid (AA), have significant roles in determining the physiological functioning of the human body. These are often analyzed through clinical lab-based procedures which are bulky and require skilled technicians. In view of this, the design, development, and fabrication of a portable, cost-effective, user-friendly, and disposable device for electro-analytical detection, leading to point-of-care (POC) detection of these metabolic biomarkers is a pressing need. This work reports a laser-induced reduced graphene oxide (LIrGO) based miniaturized paper device fabricated by laser ablation of a lab-grade paper using a blue diode laser (450 nm). A three-electrode electrochemical platform was designed with the LIrGO electrodes, whereby bare rGO electrodes were employed as working and counter electrodes, and Ag/AgCl ink-coated rGO was used as the reference electrode. The device was characterized morphologically by Scanning Electron Microscopy (SEM) and electrochemically by a potentiostat. The prepared device was subjected to electrochemical sensing of Dopamine (DA), Uric Acid (UA), and Ascorbic Acid (AA). Furthermore, the effects of several sensory parameters, such as concentration, pH, and interference, were analyzed. A linear range of 10- [Formula: see text] was obtained for all three analytes with the limit of detection (LoD) being [Formula: see text], [Formula: see text], [Formula: see text], and the limit of quantification (LoQ) being [Formula: see text], [Formula: see text], [Formula: see text] for DA, UA and AA, respectively. Finally, the device was tested for non-interference with co-analytes and validated by testing a real sample of human blood serum. This work demonstrates a proof-of-principle of utilizing bare LIrGO for selective sensing which will open door to multiplexed and POC sensing.


Asunto(s)
Dopamina , Grafito , Humanos , Ácido Úrico , Técnicas Electroquímicas , Grafito/química , Rayos Láser , Electrodos , Ácido Ascórbico/análisis , Ácido Ascórbico/química , Biomarcadores
18.
IEEE Trans Nanobioscience ; 22(2): 301-307, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-35788459

RESUMEN

Ammonia is one of the most prominent and hazardous water pollutants; hence its selective and sensitive detection in water is crucial for monitoring water quality and determining its usability. In the present work, a simple, cost-effective electrochemical sensor for the detection of ammonia is presented. Multi-walled carbon nanotubes modified ultra-micro-carbon thread electrode (UME/MWCNT) has been realized. The electro-catalytic activity of ammonia is studied by voltammetry and amperometry techniques and the results are presented. The microscopic characterization of UME/MWCNT for surface morphology analysis was also carried out. Further, the UME/MWCNT based electrochemical sensor was tested for its practical application by exploring various parameters like the effect of scan rate, pH and interference from co-existing bio-chemicals like nitrate, nitrite, phosphate, hydrazine, H2 [Formula: see text] uric acid, ascorbic acid and dopamine along with real sample analysis. The developed sensor can efficiently detect ammonia in a linear range of [Formula: see text] to 1 mM which is well within the permissible safe drinking water limit. The limit of detection (LoD) and limit of quantification (LoQ) obtained for the developed sensor were [Formula: see text] and [Formula: see text] respectively. The negligible interference, good reproducibility, and appreciable recovery values indicated the potential of the developed UME for real-time ammonia detection. As a flexible electrode, UME can be further modified and fabricated as a microfluidic or a miniaturized device for a portable electrochemical sensing platform in future.


Asunto(s)
Amoníaco , Nanotubos de Carbono , Técnicas Electroquímicas , Calidad del Agua , Nanotubos de Carbono/química , Reproducibilidad de los Resultados , Electrodos , Límite de Detección
19.
IEEE Trans Nanobioscience ; 22(1): 149-154, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-35476572

RESUMEN

Snake bite is a serious medical emergency often leading to untimely fatalities. Serotherapy is the only treatment method adapted for this, whose efficacy depends on identification of the Snake species and venom type. As a specific antivenom has to be implicated for saving the victim, in most of the cases, such identification is challenging, thus, leading to mortality due to delay in treatment or side effects of injecting polymeric non-specific antivenom. Therefore, a point-of-care, venom specific detection device could be an impactful diagnostic tool. Herein, a prototype of miniaturized electrochemical sensing platform is presented for detection of Crotaline, venom from various common pit viper snakes. A three electrode based micro-platform with carbon fibre microelectrode, modified with mesoporous carbon, embedded and laminated in commercial OHP sheet, has been developed. The dimensions of the miniaturized platform was 25 mm ×35 mm, size of electrode was 0.5 mm ×25 mm with an electrochemical testing zone of diameter 10 mm, electrode spacing as 3 mm. The microscopic characterization revealed immobilization of porous carbon on fine fibrous structure. The device gave highly stable and sensitive electro-catalytic oxidation of Crotaline at E'= at 0.81 V, and provided a linear range of 50- [Formula: see text], limit of detection as [Formula: see text] and limit of quantification as [Formula: see text]. The device exhibited negligible interference from physiological blood serum biochemicals, high stability and reproducibility. Further, real blood serum samples, analysis via standard addition approach, was performed which showcased appreciable recovery values confirming the practical applicability of the device.


Asunto(s)
Antivenenos , Venenos de Serpiente , Antivenenos/uso terapéutico , Fibra de Carbono , Microelectrodos , Reproducibilidad de los Resultados , Carbono
20.
Biomicrofluidics ; 16(6): 061505, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36483020

RESUMEN

With the advent of cyber-physical system-based automation and intelligence, the development of flexible and wearable devices has dramatically enhanced. Evidently, this has led to the thrust to realize standalone and sufficiently-self-powered miniaturized devices for a variety of sensing and monitoring applications. To this end, a range of aspects needs to be carefully and synergistically optimized. These include the choice of material, micro-reservoir to suitably place the analytes, integrable electrodes, detection mechanism, microprocessor/microcontroller architecture, signal-processing, software, etc. In this context, several researchers are working toward developing novel flexible devices having a micro-reservoir, both in flow-through and stationary phases, integrated with graphanized zones created by simple benchtop lasers. Various substrates, like different kinds of cloths, papers, and polymers, have been harnessed to develop laser-ablated graphene regions along with a micro-reservoir to aptly place various analytes to be sensed/monitored. Likewise, similar substrates have been utilized for energy harvesting by fuel cell or solar routes and supercapacitor-based energy storage. Overall, realization of a prototype is envisioned by integrating various sub-systems, including sensory, energy harvesting, energy storage, and IoT sub-systems, on a single mini-platform. In this work, the diversified work toward developing such prototypes will be showcased and current and future commercialization potential will be projected.

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