Hydrogen peroxide biosensor based on microperoxidase-11 immobilized on flexible MWCNTs-BC nanocomposite film

Abstract

In the present work, we report on an experimental study of flexible nanocomposite film for electrochemical detection of hydrogen peroxide (H2O2) based on bacterial cellulose (BC) and multi-walled carbon nanotubes (MWCNTs) in combination with microperoxidase-11 (MP-11). MWCNTs are used to functionalize BC and provide a flexible conductive film. On the other hand, BC can improve MWCNTs׳ biocompatibility. The investigation shows that MP-11 immobilized on the flexible film of MWCNTs-BC can easily present a pair of well-defined and quasi-reversible redox peaks, revealing a direct electrochemistry of MP-11 on the nanocomposite film. The apparent heterogeneous electron-transfer rate constant ks is estimated to be 11.5s(-1). The resulting flexible electrode presents appreciated catalytic properties for electrochemical detection of H2O2, comparing to traditional electrodes (such as gold, glassy carbon electrode) modified with MP-11. The proposed biosensor exhibits a low detection limit of 0.1 µM (at a signal-to-noise ratio of 3) with a linear range of 0.1-257.6 µM, and acquires a satisfactory stability.

Keywords: Bacterial cellulose; Biosensor; H(2)O(2) detection; Microperoxidase-11; Multi-walled carbon nanotubes.