Ashish Gothwal

Preparation of Electrochemical Biosensor for Detection of Organophosphorus Pesticides

Polyvinyl chloride (PVC) can be used to develop reaction beaker which acts as electrochemical cell for the measurement of OP pesticides. Being chemically inert, corrosion resistant, and easy in molding to various shapes and size, PVC can be used for the immobilization of enzyme. Organophosphorus hydrolase was immobilized covalently onto the chemically activated inner surface of PVC beaker by using glutaraldehyde as a coupling agent. The carbon nanotubes paste working electrode was constructed for amperometric measurement at a potential of +0.8 V. The biosensor showed optimum response at pH 8.0 with incubation temperature of 40°C. K m and I max for substrate (methyl parathion) were 322.58 µM and 1.1 µA, respectively. Evaluation study showed a correlation of 0.985, which was in agreement with the standard method. The OPH biosensor lost 50% of its initial activity after its regular use for 25 times over a period of 50 days when stored in 0.1 M sodium phosphate buffer, pH 8.0 at 4°C. No interference was observed by interfering species.

Bilirubin enzyme biosensor: potentiality and recent advances towards clinical bioanalysis

Bilirubin detection plays a major role in healthcare. Its high concentration in human serum is lethal and must be determined accurately. Clinically, it is vital for assessing patients with deleterious health conditions such as jaundice or icterus, hepatitis, mental disorders, cerebral palsy and brain damage especially in the case of neonates. In evaluating the drawbacks regarding the conventional methodology of bilirubin detection, there is need for a superior analytical tool. Bilirubin oxidase (BOx)-based sensors have been designed for the ultrasensitive analysis of bilirubin and quality deliverance of treatment and this review highlights the different mechanisms of bilirubin detection using different modified electrodes. Further, it also addresses the exploitation of highly attractive electrocatalytic properties of elite nanoparticles such as gold and zirconia- coated silica nanoparticles in enhancing the reproducibility and specificity of bilirubin biosensors.

Enzyme-Based Ultrasensitive Electrochemical Biosensors for Rapid Assessment of Nitrite Toxicity: Recent Advances and Perspectives

ABSTRACT In the present era of rapid international globalization and industrialization, intensive use of nitrite as a fertilizing agent in agriculture, preservative, dyeing agent, food additive and as corrosion inhibitor in industrial sectors is adversely effecting environment, natural habitats and human health. The issue of toxicity and carcinogenicity due to excessive ingestion of nitrites via the dietary intake has led to an imminent need for its efficient real-time monitoring in situ. Nitrite detection employing electrochemical biosensors has been gaining high credibility in the field of clinical research. Nitrite biosensors have emerged as an outstanding choice for portable point of care testing of nitrite quantification owing to the excellent properties, such as rapidity, miniaturization, ultra-low limits of detection, multiplexing and enhanced detection sensitivity. The article is enclosed with an interesting outlook on latest emerging trends in the development of nitrite biosensors utilizing nanomaterials, such as metal nanoparticles, carbon nanotubes, metal oxide nanoparticles, nanocomposites, polymers and biomaterials. The present review embarks on the highlights relevant to the nitrite quantification in real samples, then proceeds with a meticulous description of the most pertinent electrochemical nitrite biosensors, which have been proposed by adopting diverse materials and strategies of fabrication and finally end with the achievements and future outlook signifying the application of these nanoengineered biosensors for environmental surveillance and human safety.

Recent trends and perspectives in enzyme based biosensor development for the screening of triglycerides: a comprehensive review

Abstract Clinical manifestations of the elevated plasma triacylglycerol (TG) include a greater prevalence of atherosclerotic heart disease, acute pancreatitis, diabetes mellitus, hypertension, and ischemic vascular disease. Hence, these significant health troubles have attracted scientific attention for the precise detection of TG in biological samples. Numerous techniques have been employed to quantify TG over many decades, but biosensors hold the leading position owing to their superior traits such as highly specific recognition for target molecules, accuracy, minituarization, small sample requirement and rapid response. Enzyme-based electrochemical biosensors represent an instantaneous resolution for the foremost bottlenecks constraining laboratory prototypes to reach real time bedside applications. We highlight the choice of transducers and constructive strategies to design high-performance biosensor for the quantification of triglycerides in sera and early diagnosis of health problems related to it. In the present review, a small effort has been made to emphasize the significant role of enzymes, nanostructured metal oxides, graphene, conducting polypyrrole, nanoparticles, porous silicon, EISCAP and ENFET in enabling TG biosensors more proficient and taking a revolutionary step forward.