Catalase-Based Modified Graphite Electrode for Hydrogen Peroxide Detection in Different Beverages.

Giovanni Fusco,Riccarda Antiochia,Paolo Bollella,Franco Mazzei,Gabriele Favero,Cristina Tortolini

doi:10.1155/2016/8174913

Abstract

A catalase-based (NAF/MWCNTs) nanocomposite film modified glassy carbon electrode for hydrogen peroxide (H2O2) detection was developed. The developed biosensor was characterized in terms of its bioelectrochemical properties. Cyclic voltammetry (CV) technique was employed to study the redox features of the enzyme in the absence and in the presence of nanomaterials dispersed in Nafion® polymeric solution. The electron transfer coefficient, α, and the electron transfer rate constant, k s, were found to be 0.42 and 1.71 s−1, at pH 7.0, respectively. Subsequently, the same modification steps were applied to mesoporous graphite screen-printed electrodes. Also, these electrodes were characterized in terms of their main electrochemical and kinetic parameters. The biosensor performances improved considerably after modification with nanomaterials. Moreover, the association of Nafion with carbon nanotubes retained the biological activity of the redox protein. The enzyme electrode response was linear in the range 2.5–1150 μmol L−1, with LOD of 0.83 μmol L−1. From the experimental data, we can assess the possibility of using the modified biosensor as a useful tool for H2O2 determination in packaged beverages.

Highlights

In recent years, many researchers focused their activity on developing new tools to detect H2O2, as an oxidases reaction byproduct and as a conservative compound in food and drugs [1, 2]
We report the development of a biosensor for H2O2monitoring based on the immobilization of catalase in a Nafion film containing dispersed functionalized MWCNTs-COOH
The effect on the improvement of electrochemical performances by using nanomaterials as MWCNTs-COOH was evaluated with cyclic voltammetry measurements of the electroactive area (Ae) and of the heterogeneous standard rate constant (k0) of the different electrodes

Summary

Introduction

Many researchers focused their activity on developing new tools to detect H2O2, as an oxidases reaction byproduct and as a conservative compound in food and drugs [1, 2]. The direct reduction of H2O2at a bare sensor is not suitable for analytical measures due to its slow kinetics and high potentials required for redox reactions [44] To overcome these problems, several modified electrochemical sensors were developed. Denaturation of the redox protein could occur on the sensor surface due to the immobilization method and to the matrix composition To overcome these problems and promote the DET carbon nanotubes (CNTs), modified electrodes are widely employed as support for the physical immobilization of biological molecules to promote the DET thanks to their high surface/volume ratio and conductivity and to enhance sensors and biosensors performances [63,64,65,66,67]. The obtained biosensor was applied for the determination of hydrogen peroxide in beverages samples

Experimental

Results and Discussion

Conclusion