An electrochemical biosensor developed for the online monitoring of H2O2 based on the reduced graphene oxide-cerium dioxide nanocomposite

Abstract

A biosensor was developed for monitoring H2O2 based on reduced Graphene Oxide-Cerium Oxide (rGO-CeO2) nanocomposite (NC). The NC shows catalytic effect on the electrochemical reduction of H2O2 at 0.3 V. The effect of the NC on the electrochemical reduction of H2O2 was studied by cyclic voltammetry and compared with bare glassy carbon (GC) and GC/r-GO. Moreover, to improve the signal a complex containing copper was incorporated in the dispersion of the nanocomposite which acts as a mediator. It was found that the electrochemical reduction of H2O2 takes place at less negative potential with increased peak current attitude at GC/r-GO-mediator. The developed sensor GC/r-GO-mediator, was applied for the continuous monitoring of H2O2 by chronoamperometry. The applied potential was 0.3 V which results in the enhanced sensitivity of the developed biosensor. The developed biosensor shows good stability, and reproducibility. The reproducibility of the developed electrode was evaluated by calculation of relative standard deviation value 6.77%. The linear range was found to be 3.4 - 23.48 g/ml. Furthermore, limit of detection and limit of quantification were 0.68 g/ml and 2.27 g/ml respectively.A biosensor was developed for monitoring H2O2 based on reduced Graphene Oxide-Cerium Oxide (rGO-CeO2) nanocomposite (NC). The NC shows catalytic effect on the electrochemical reduction of H2O2 at 0.3 V. The effect of the NC on the electrochemical reduction of H2O2 was studied by cyclic voltammetry and compared with bare glassy carbon (GC) and GC/r-GO. Moreover, to improve the signal a complex containing copper was incorporated in the dispersion of the nanocomposite which acts as a mediator. It was found that the electrochemical reduction of H2O2 takes place at less negative potential with increased peak current attitude at GC/r-GO-mediator. The developed sensor GC/r-GO-mediator, was applied for the continuous monitoring of H2O2 by chronoamperometry. The applied potential was 0.3 V which results in the enhanced sensitivity of the developed biosensor. The developed biosensor shows good stability, and reproducibility. The reproducibility of the developed electrode was evaluated by calculation of relative standard deviation value 6.77%. The linear range was found to be 3.4 - 23.48 g/ml. Furthermore, limit of detection and limit of quantification were 0.68 g/ml and 2.27 g/ml respectively.