Biosensors & Bioelectronics

Modified Tin Oxide Based Bioelectrode for Reagentless Detection of Uric Acid

Abstract

Kashima Arora, Monika Tomar and Vinay Gupta

A reagentless uric acid biosensor has been realized using Copper implanted tin oxide thin film (Cu:SnO2) based matrix. The biosensing characteristics of implanted matrix have been studied using the electrochemical impedance spectroscopy and cyclic voltammetry. The prepared matrix (Cu:SnO2), because of the presence of Cu, possess redox properties so that the electron transfer from enzyme to the electrode could be accomplished without using any external mediator in the electrolyte. The developed uric acid biosensor exhibits a high sensitivity of about 0.93 mA/ mM and a linear variation in current response over a concentration range from 0.05 to 1.0 mM of uric acid besides high shelf life (~20 weeks). The Michaelis-Menten kinetic parameter (Km) is found to be relatively very low (0.12 mM), which indicates the high affinity of the fabricated bioelectrode towards the uric acid (analyte). The results highlight the importance of implanted Cu:SnO2 thin film as an attractive matrix for the realization of reagentless biosensors towards uric acid.