Potential enhancements in commercial glucose biosensors utilizing electrochemical faradaic spectroscopy: Analyzing the sum component in the EC’ mechanism

Abstract

Herein we report the use of electrochemical faradaic spectroscopy in biosensors, with application on a commercially used first-generation glucose biosensor manufactured by Zimmer and Peacock. The mechanism for the glucose sensor was explained and approximated as an EC’ mechanism, where E is for electron transfer step, whereas C’ signifies catalytical chemical step. Experimental chronoamperograms in electrochemical faradaic spectroscopy are compared to chronoamperometry, where it was found that the sum component in electrochemical faradaic spectroscopy gives higher response, resulting in better sensitivity of the sensor. Theoretical simulations give an insight of the response in electrochemical faradaic spectroscopy for an EC’ mechanism and its dependence on different parameters (dimensionless electrode kinetic parameter, mid potential, dimensionless chemical kinetic parameter). For some specific set of parameters (large electrode and catalytic reaction kinetics), theoretical chronoamperograms in electrochemical faradaic spectroscopy can become similar to the experimental. The property of the sum component to have higher response in EC’ mechanism for specific parameters is not limited only for electrochemical faradaic spectroscopy. Exemplified with square-wave voltammetry, it is shown that other pulse techniques for an EC’ mechanism can also result with higher sum component. Hence, for better sensitivity in quantitative analysis in EC’ mechanism, one should quantify the sum component.