Ahmad Tariq Jameel

Aligarh Muslim University, India

Title: Enzyme-Inhibition Based Electrochemical Bio-sensing of Organophosphorus Pesticides – Theory and Mechanism

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Biography

Ahmad Tariq Jameel is currently Professor at the Department of Chemical Engineering, Aligarh Muslim University (AMU), India. Dr. Jameel obtained his Ph.D. in Chemical Engineering from the Indian Institute of Technology Kanpur. He has served in the past as full time faculty at several universities in India, Malaysia, Oman and Saudi Arabia.

Dr. Jameel’s current research interests include: Development of immobilized enzyme based nano-biosensors; convection-diffusion-reaction in biocatalyst pellets/nano-biocatalyst; immobilization of enzymes/cells on nanostructures/gel matrices; nonlinear stability & dynamics of thin liquid film flows, etc. He has published and/or presented over 80 research papers in international and national journals and conference proceedings, besides several book chapters and edited books to his credit. He is a member of the International Association of Colloid and Interface Scientists (IACIS) and the Canadian Society for Chemical Engineering (CSChE). He has been actively involved in curricula development for Chemical and Bioengineering programs.  

Abstract

In modern agricultural practices, organophosphorus compounds (OPs) are widely used as pesticide and insecticide. However, an excess of OPs may become nero-toxic to humans and many other live forms. Traditional methods of detection of OPs are cumbersome and expensive. Lately, biosensor technology being developed are portable, efficient and economical. Currently, most biosensors for OPs are based on the inhibition of acetylcholinesterase (AChE) extracted from animal sources. This can be easily replaced with the plant-esterase as sensing material because plant esterase can be extracted easily from plant sources. Metal and carbon based nanomaterials are being widely used as immobilization support owing to biocompatibility and enhanced electron transfer ability for sensitive electrochemical detection. This study aims to explore and quantify the effectiveness of an immobilized plant esterase (alpha-naphthyl acetate esterase (ANAE)) on multi-walled carbon nanotube (MWCNT) coated on Screen Printed Carbon Electrode (SPCE) for efficient detection of pesticides in food and environment. The OPs are known to inhibit the plant esterase. The ANAE was extracted from wheat flour and purified by polyethylene glycol (PEG)/salt aqueous two-phase separation process. The Michaelis-Menten kinetics and inhibition kinetics of free ANAE was investigated, and appropriate kinetic models proposed. An irreversible inhibition mechanism lead to the determination of the kinetic constants for the inhibition of ANAE by OPs. The kinetics of immobilized ANAE-MWCNT is being investigated. The hydrolysis of alpha naphthyl acetate by ANAE in the presence of inhibitors, i.e., OP pesticides produces an electrical signal that depends on the OPs concentration and is measured amperometrically. Sensitivity, detection limit and response time of the biosensor in the presence of OPs will be quantified. The research outcomes include: identification of appropriate kinetic model for the inhibition of ANAE; the characterization of the ANAE-MWCNT-SPCE electrode for the efficient detection of OPs; the identification of optimal parameters.