Covalent immobilization of glucose oxidase enzyme onto a carbon paste electrode for kinetic study of starch hydrolysis

Abstract

A glucose biosensor is developed by using covalent immobilization of glucose oxidase enzyme onto a carbon paste electrode which is made by DropSens Instrument. The screen printed electrode which is designed by DropSens is used in this project. There are three electrodes which are counter electrode (CE) made by carbon paste, reference electrode (RE) made by silver paste and the third one is working electrode (WE) made by carbon paste. The sol gel is prepared and is dropped onto the center of the electrode where the working electrode is placed. The sol gel is used as membrane for glucose oxidase enzyme to immobilize. The best method is choosed as sandwich type of immobilization. The sandwich type of immobilization has three layer which is layer one sol gel with ferrocene, layer two is glucose oxidase enzyme and the third layer is sol gel without ferrocene. The method is benefit to produce the better and safe place for enzyme to immobilize and safe from denature, leaching or wash out. The Dropview software is used for measurement which is provided by DropSens Instrument. The cyclic voltammetry method is used while doing the measurement in this project. The standard curve for glucose is obtained by measuring the glucose solution which is prepared at different concentrion 2, 4, 6, 10, 15, 20, 30,40, and 50 mM. The result is obtained and is compared with the next measurement which is for kinetic study of starch hydrolysis. The kinetic study of starch hydrolysis is shown how the reaction of starch and alpha amylase will produce glucose at different incubation time which is at 1, 5, 15, 30, 60, and 120 minutes. The overall result is shown that the highest concentration of glucose solution is produced the highest current and the longest incubation time for starch hydrolysis is produced the highest current which mean the more glucose is produced.