Direct electrochemistry of hemoglobin on graphene/Fe3O4 nanocomposite-modified glass carbon electrode and its sensitive detection for hydrogen peroxide

Yuqiao Wang,Yuan Zhang,Dan Yao,Yueming Sun,Huijun Zhang,Junjie Pu,Xiaorui Gao

doi:10.1007/s10008-012-1939-5

Abstract

Graphene/Fe3O4 nanocomposite was prepared for the immobilization of hemoglobin (Hb) to improve the electron transfer between Hb and glass carbon electrode (GCE). The characterization of nanocomposites was described by transmission electron microscopy, Fourier transform infrared, Raman spectroscopy, and X-ray photoelectron spectroscopy, respectively. The electrochemistry of Hb on the graphene/Fe3O4-based GCE was investigated by cyclic voltammetry and amperometric measurement. The modified electrode showed a wide linear range from 0.25 μmol/L to 1.7 mmol/L with a correlation coefficient of 0.9967. The detection limit of the H2O2 biosensor was estimated at 6.0 × 10−6 mol/L at a signal-to-noise ratio of 3.

Highlights

Graphene (GE), with one-atom-thick planar sheets of sp2bonded carbon atoms, has attracted much attention recently due to its high surface area, excellent electrical conductivity, Y
The amperometric H2O2 biosensor based on GE/Fe3O4/Hb glass carbon electrode (GCE) was fabricated for investigating the effect of the nanocomposite on the direct electrochemistry of Hb, including the linear range, detection limitation, solution pH, stability, and reproducibility towards H2O2
The results prove that the oxygen functional groups of graphite oxide (GO) are almost entirely removed from GE with poly(diallyldimethylammonium chloride) (PDDA) acting as reducing reagent

Summary

Introduction

Graphene (GE), with one-atom-thick planar sheets of sp2bonded carbon atoms, has attracted much attention recently due to its high surface area, excellent electrical conductivity, Y. The objective of this work was to explore the ability of the GE/Fe3O4 nanocomposite in immobilizing Hb on the electrode surface and promoting direct electron transfer between Hb and electrodes. We prepared Fe3O4 and added it to the reduction process, during which process the graphene oxide was reduced to GE by PDDA. The GE/Fe3O4 nanocomposite was modified onto a glass carbon electrode (GCE), where Hb was immobilized by drop casting.

Objectives

Results

Conclusion