A Highly Sensitive and Selective Hydrogen Peroxide Biosensor Based on Gold Nanoparticles and Three-Dimensional Porous Carbonized Chicken Eggshell Membrane.

Di Zhang,Haitao Li,Penghui Du,Hongbin Cao,Mingjie Li,Zhuangjun Fan,Chenming Liu,He Zhao,Yuping Li,Serge Muyldermans

doi:10.1371/journal.pone.0130156

Abstract

A sensitive and noble amperometric horseradish peroxidase (HRP) biosensor is fabricated via the deposition of gold nanoparticles (AuNPs) onto a three-dimensional (3D) porous carbonized chicken eggshell membrane (CESM). Due to the synergistic effects of the unique porous carbon architecture and well-distributed AuNPs, the enzyme-modified electrode shows an excellent electrochemical redox behavior. Compared with bare glass carbon electrode (GCE), the cathodic peak current of the enzymatic electrode increases 12.6 times at a formal potential of −100mV (vs. SCE) and charge-transfer resistance decreases 62.8%. Additionally, the AuNPs-CESM electrode exhibits a good biocompatibility, which effectively retains its bioactivity with a surface coverage of HRP 6.39×10−9 mol cm−2 (752 times higher than the theoretical monolayer coverage of HRP). Furthermore, the HRP-AuNPs-CESM-GCE electrode, as a biosensor for H2O2 detection, has a good accuracy and high sensitivity with the linear range of 0.01–2.7 mM H2O2 and the detection limit of 3μM H2O2 (S/N = 3).

Highlights

Horseradish peroxidase (HRP), a heme-containing enzyme, is commonly applied for amperometric biosensors due to its redox activity [1, 2]
The macropores and micropores on the carbon plate form a hierarchical porous structure, which are uniformly distributed in the glass carbon electrode (GCE)
Given the advantages of the large specific surface area and good conductivity of AuNPs, the AuNPs–chicken eggshell membrane (CESM)-GCE electrode exhibits enhanced current response [30]. These results indicate that the CESM and AuNPs act as promoters for successfully establishing direct electron transfer and dramatically enhance the electrochemical response

Summary

Introduction

Horseradish peroxidase (HRP), a heme-containing enzyme, is commonly applied for amperometric biosensors due to its redox activity [1, 2]. A HRP molecular (42 kDa), is characterized by 308 amino acid residues with a ferric heme (iron protoporphyrin type IX) prosthetic group. It plays an important role in the activation of substrate and the subsequent redox reaction [2, 3]. The heterogeneous direct electron transfer (DET) between the redox sites of enzyme and the electrode, which is the basis for fabricating various amperometric biosensors and understanding the redox process, has drawn more.

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