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| 2. |
- Ahmad, Farook, et al.
(författare)
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Development of prototype wireless transmission measurement for glucose in subcutaneous and brain striatum
- 2008
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Ingår i: Electroanalysis. - : Wiley. - 1040-0397 .- 1521-4109. ; 20:9, s. 1008-1015
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Tidskriftsartikel (refereegranskat)abstract
- Monitoring of glucose in subcutaneous and brain striatum have been extensively studied in the past. While biocompatibility was one of the limitations, others included the messy measuring equipments preclude monitoring in a complex environment. This study tried to establish an amperometric measurement of glucose in pre- and post-insulin-administration on diabetic and hyperglycemia rats via wireless. The results have indicated that the wireless sensing kit used was capable of monitoring glucose in both subcutaneous and brain. The physiological data have also shown a new insight on the fabrication of implantable glucose sensors.
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| 3. |
- Ahmed Khand, Aftab, et al.
(författare)
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Synthesis of Sheet Like Nanostructures of NiO Using Potassium Dichromate as Surface Modifying Agent for the Sensitive and Selective Determination of Amlodipine Besylate (ADB) Drug
- 2021
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Ingår i: Electroanalysis. - : WILEY-V C H VERLAG GMBH. - 1040-0397 .- 1521-4109. ; 33:5, s. 1121-1128
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Tidskriftsartikel (refereegranskat)abstract
- The monitoring of hypertension drugs is very critical and important to sustain a healthy life. In this study, we have synthesized nickel oxide (NiO) nanostructures using potassium dichromate as surface modifying agent by hydrothermal method. These NiO nanostructures were found highly active for the oxidation of ADB besylate (ADB). The unit cell structure and morphology were investigated by scanning electron microscopy (SEM) and powder X-ray diffraction (XRD) techniques. The SEM study has confirmed the nano sheet like morphology and XRD analysis has described the cubic unit arrays of NiO. After the physical characterization, NiO nanostructures were used to modify the surface of glassy carbon electrode (GCE) by drop casting method. Then cyclic voltammetry (CV) was used to characterize the electrochemical activity of NiO nanostructures in the0.1 M phosphate buffer solution of pH 10.0 and a well resolved oxidation peak was identified at 0.70 V. The linear range for the NiO nanostructures was observed from 20-90 nM with a regression coefficient of 0.99 using CV. The calculated limit of detection (LOD) was 2.125 nM and the limit of quantification (LOQ) was 4.08 nM. Further to validate the CV calibration plot, an amperometry experiment was performed on the NiO nanostructures and sensors exhibited a linear range of 10 nM to 115 nM with LOD of 1.15 nM. The proposed approach was successfully used for the determination of ADB from commercial tablets and it reveals that the sensor could be capitalized to monitor ADB concentrations from pharmaceutical products. The use of potassium dichromate as a surface modifying agent for the metal oxide nanostructures may be of great interest to manipulate their crystal and surface properties for the extended range of biomedical and energy related applications.
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| 4. |
- Al-Khafaji, Q A M, et al.
(författare)
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An Electrochemical Immunoassay for HER2 Detection
- 2012
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Ingår i: Electroanalysis. - : Wiley-VCH Verlag Berlin. - 1040-0397 .- 1521-4109. ; 24:4, s. 735-742
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, a simple and sensitive approach for human epidermal growth factor receptor 2 (HER2) detection is presented, using antibody-functionalised magnetic beads coupled to screen-printed cells. The immunoassay is based on a sandwich format in which a primary monoclonal antibody anti-HER2 is coupled to protein A modified magnetic beads. The modified beads are then used to capture the protein from the sample solution and a sandwich assay is performed by adding a secondary monoclonal antibody anti-HER2 labelled with biotin. The enzyme alkaline phosphatase (AP) conjugated with streptavidin and its substrate (1-naphthyl-phosphate) are then used for the electrochemical detection by differential pulse voltammetry (DPV). The experimental conditions for the immunoassay were optimised. The performance of the assay in terms of sensitivity, reproducibility and selectivity has been studied in buffer and serum samples from hospital patients.
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| 5. |
- Ali Soomro, Razium, et al.
(författare)
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Glutaric Acid Assisted Fabrication of CuO Nanostructures and their Application in Development of Highly Sensitive Electrochemical Sensor System for Carbamates
- 2016
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Ingår i: Electroanalysis. - : WILEY-V C H VERLAG GMBH. - 1040-0397 .- 1521-4109. ; 28:7, s. 1634-1640
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Tidskriftsartikel (refereegranskat)abstract
- This work describes the fabrication of unique arrow head shaped CuO nanostructures using simple hydrothermal treatment method. The highly attractive features were obtained by the application of glutaric acid utilised simultaneous as template and functionalising agent. The functionalised nanostructures were known to possess excellent potential towards the electro-catalytic oxidation of carbofuran pesticide. The generated intense electrochemical signal with lower potential value enabled sensitive and selective determination of carbofuran up to 1 x 10(-3) mu M with wide sensing window in range of 0.01 to 0.16 mu M. The feasibility of the developed sensor system for the practical application was also studied by testing its potential in real sample extracts of various vegetables. The excellent recoveries demonstrated the analytical robustness of the developed sensor system. The sensor system utilises a new and simple approach towards sensitive determination of toxic pesticides reflecting its wide spectrum application in various fields.
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| 6. |
- Amin, Sidra, et al.
(författare)
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Functional Nickel Oxide Nanostructures for Ethanol Oxidation in Alkaline Media
- 2020
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Ingår i: Electroanalysis. - : John Wiley & Sons. - 1040-0397 .- 1521-4109. ; 32:5, s. 1052-1059
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Tidskriftsartikel (refereegranskat)abstract
- Nickel oxide (NiO) nanostructures are employed in the basic medium for the oxidation of ethanol. A variety of NiO nanostructures are synthesized by wet chemical growth method, using different hydroxide (OH−) ion sources, particularly from ammonia, hexamethylenetetramine, urea and sodium hydroxide. The use of urea as (OH−) ion source results in flower‐like NiO structures composed by extremely thin nanowalls (thickness lower than 10 nm,), which demonstrated to be the most active for ethanol oxidation. All the samples exhibit NiO cubic phase, and no other impurity was detected. The cyclic voltammetry (CV) curves of NiO nanostructures were found linear over the concentration range 0.1–3.5 mM (R2=0.99) of ethanol, with the limit of detection estimated to be 0.013 mM for ethanol. The NiO nanostructures exhibit a selective signal towards ethanol oxidation in the presence of different members of alcohol family. The proposed NiO nanostructures showed a significant practicality for the reproducible and sensitive determination of ethanol from brandy, whisky, mixture of brandy and rum, and vodka samples. The nanomaterial was used as a surface modifying agent for the glassy carbon electrode and it showed a stable electro‐oxidation activity for the ethanol for 16 days. These findings indicate that the presented NiO nanomaterial can be applied in place of noble metals for ethanol sensing and other environmental applications (like fuel cells).
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| 7. |
- Antiochia, Riccarda, et al.
(författare)
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Composite Material Based on Macroporous Polyaniline and Osmium Redox Complex for Biosensor Development
- 2014
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Ingår i: Electroanalysis. - : Wiley. - 1040-0397. ; 26:7, s. 1623-1630
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Tidskriftsartikel (refereegranskat)abstract
- Here the feasibility of layers based on the conducting polymer polyaniline (PANI) as component of glucose biosensors using glucose oxidase (GOx) as enzyme and [Os(bpy)(2)(4-aminomethylpyridine)Cl]PF6 (OsCmplx) as electrochemical mediator, is evaluated. Particularly, PANI was employed to obtain a nanostructured macroporous material (m-PANI) around polystyrene nanoparticles taken as template and the mediator was co-immobilized during the polymerizing procedure. The GOx biosensor based on OsCmplx modified m-PANI provides a linear response to glucose concentration in the range 5 up to 65 mM with a sensitivity of 3.54 mu A/mM/cm(2) (on a projected geometric area=0.07 cm(2)), an LOD of 0.8 mM and a good precision (%RSD <= 7, n=5); the biosensor is stable showing a decrease of 10% to the value of the sensitivity after 15 days of use and of about 50% after 40 days.
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| 8. |
- Aslan, Sema, et al.
(författare)
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Development of an Osmium Redox Polymer Mediated Bioanode and Examination of Its Performance in Gluconobacter oxydans Based Microbial Fuel Cell
- 2017
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Ingår i: Electroanalysis. - : Wiley. - 1040-0397. ; 29:6, s. 1651-1657
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Tidskriftsartikel (refereegranskat)abstract
- Gluconobacter oxydans (G. oxydans) cells together with an osmium redox polymer (ORP) [Osmium (2,2'-bipyridine)2(poly-vinylimidazole)10Cl]Cl were combined with a glassy carbon paste electrode (GCPE) to form a bioanode for a microbial fuel cell (MFC) based on G. oxydans. Although there are G.oxydans/ ORP combined bioanode in the literature, as far as it is known, this system is the first one where G.oxydans/ORP bioanode is combined with a cathode and a MFC is formed. After the optimization of experimental parameters, analytical characteristics of ORP/G. oxydans/GCPE bioanode were investigated. ORP/G. oxydans/GCPE showed two linear ranges for ethanol substrate as 1.0-30mM (R2=0.902) and 30-500mM (R2=0.997) and analytical range as 1.0-1000mM. Limit of detection (3.0s/m) and limit of quantification (10s/m) values were calculated as 1.29mM and 4.30mM respectively where the RSD value was 1.16% for n=5. Combining the developed bioanode in the presence of 5.0mM K3Fe(CN)6 mediator with a Pt wire cathode a double compartment MFC was obtained via a salt bridge. G. oxydans/GCPE bioanode based MFC had maximum power density of 0.133 μW cm-2 (at 33.5 mV), maximum current density as 8.73 μA cm-2 and OCP value of 156 mV. On the other hand, ORP/G. oxydans/GCPE based MFC showed maximum power density as 0.26 μW cm-2 (at 46.8 mV), maximum current density as 15.079 μA cm-2 and OCP value of 176 mV.
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| 9. |
- Bhattacharyay, Dipankar, et al.
(författare)
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Disposable amperometric sensors for thiols with special reference to glutathione
- 2008
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Ingår i: Electroanalysis. - : John Wiley andamp;amp; Sons, Ltd. - 1040-0397 .- 1521-4109. ; 20:18, s. 1947-1952
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Tidskriftsartikel (refereegranskat)abstract
- The antioxidant reduced glutathione tripeptide is conventionally called glutathione (GSH). The oxidized form is a sulfur-sulfur linked compound. known as glutathione disulfide (GSSG). Glutathione is an essential cofactor for antioxidant enzymes. it provides protection also for the mitochondria against endogenous oxygen radicals. The ratio of these two forms can act as a marker for oxidative stress. The majority of the methods available for estimation of both the forms of glutathione are based on colorimetric and electrochemical assays. In this study, electrochemical sensors were developed for the estimation of both GSH and GSSG. Two different types of transducers were used: i) screen-printed three-electrode disposable sensor (SPE) containing carbon working electrode, carbon counter electrode and silver/silver chloride reference electrode; ii) three-electrode disposable system (CDE) consisting of three copper electrodes. 5.5-dithlobis(2-nitrobenzoic acid) (DTNB) was used as detector element for estimation of total reduced thiol content. The enzyme glutathione reductase along with a co-enzyme reduced nicotinamide adenine dinucleotide phosphate was used to estimate GSSG. By combining the two methods GSH can also be estimated. The detector elements were immobilized on the working electrodes of the sensors by bulk polymerization of acrylamide. The responses were observed amperometrically. The detection limit for thiol (GSH) was less than 0.6 ppm when DTNB was used. whereas for GSSG it was less than 0.1 ppm.
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| 10. |
- Bishnoi, Sunita, et al.
(författare)
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Electrochemical Sensing of Chlorpyrifos, a Carcinogen Responsible for Breast Cancer, in Milk and Plasma of Lactating Mothers
- 2023
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Ingår i: Electroanalysis. - : Wiley. - 1040-0397 .- 1521-4109. ; 35:2
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Tidskriftsartikel (refereegranskat)abstract
- In view of the increase in breast cancer cases at the global level, electrochemical sensing of the carcinogenic pesticide, chlorpyrifos (CPF) in breast milk is proposed. The determination is based on the nucleophilic substitution reaction of pralidoxime (PAM) with CPF. The proposed method offers a linear concentration range of 0.002 to 0.08 μmol/L. The limit of detection and limit of quantification was found to be 0.05×10−9 and 0.167×10−9M, respectively. The offered “unmodified edge plane pyrolytic graphite sensor” proved to be a better substrate than the earlier reported modified sensors. The limit of detection for the proposed method was found to be nearly fifty times lower than reported at modified electrodes. The interference study proved the adequate selectivity of the offered sensor. The sensor has good stability and reproducibility along with high sensitivity. The offered sensor is very useful for cancer hospitals, pesticide industries, and the study of environmental toxicity-related issues.
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