Electrochemical Biosensors Using Multi-Enzyme Cascade Reactions

Abstract

In this work, we demonstrate the development of reliable biosensing methods using multi-enzyme cascade reactions. The cascade reactions result in the generation of an amperometric signal that could be attributed to the selective interaction of the analyte with the enzyme biosensing platform. An example of such a multi-enzyme cascade based amperometric biosensor is an enzymatic methyl salicylate biosensor. Methyl salicylate is an important chemical marker for biotic stress in plants. Here we report the detection of methyl salicylate by three different methods. First two methods involve two enzyme cascade reactions for indirect detection of methyl salicylate through alcohol oxidase/horse radish peroxidase enzyme couple or salicylate hydroxylase/tyrosinase enzyme couple. The third method involves the use of 3 enzyme system that additionally includes an esterase for direct hydrolysis of methyl salicylate for subsequent reactions. The presentation will discuss the mechanisms behind the amperometric detection in each of the above biosensing methods