A Mexacarbate Electrochemical Biosensor on Carbon Materials Based on a Functionalized Multiwalled Carbon Nanotube Modified Glassy Carbon Electrode

Abstract

The commercial multi-walled carbon nanotube (MWCNT) was carboxylated using sulphuric and nitric acid and characterized by various techniques such as scanning eletron spectroscopy, Infra-red spectroscopy and atomic force microscopy. The acid functionalized multiwalled carbon nanotube serves as the effective matrix for the sensing of carbamate pesticide namely mexacarbate. The electrochemical oxidation of mexacarbate at GCE and MWCNT/GCE follows heterogeneous electron transfer reaction. Different experimental parameters such as the effect of scan rate and pH were studied. Rotating disk electrode voltammetry studies confirms the one-electron transfer reaction. The sensor calibration plot for mexacarbamate was constructed by means of pulse technique. The acid functionalized multiwalled carbon nanotube sensor was applied to real water sample with the recovery percentage of 85-89%.