Biosensors & Bioelectronics

In this work, Poly eosin modified carbon paste electrode was prepared by electropolymerisation method by using cyclic voltammetry technique. This poly (Eosin) modified CPE exhibited an excellent electrocatalytic activity towards the oxidation PA and FA in presence of EP in 0.2M PBS at pH 7.0. The effect of pH and sweep rate was studied. The limit of detection of PA and FA were found to be 0.06 and 0.04 μM, respectively. An electrochemical simultaneous separation was observed in a binary mixture containing PA, FA and EP and interference study was done by differential pulse voltammetry technique. Finally, the prepared fabricated sensor exhibits good sensitivity, and selectivity.

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.