Direct electrochemistry and enhanced electrocatalysis of horseradish peroxidase based on flowerlike ZnO–gold nanoparticle–Nafion nanocomposite

We developed a new flowerlike ZnO–gold nanoparticles (GNPs)–Nafion nanocomposite which can promote the direct electron transfer of horseradish peroxidase (HRP) immobilized in the film effectively. The cyclic voltammetric results show that HRP entrapped in the composite could undergo a direct quasi-r...

Full description

Saved in:
Bibliographic Details
Published in:Sensors and actuators. B, Chemical Chemical, 2009-02, Vol.136 (1), p.158-162
Main Authors: Xiang, Cuili, Zou, Yongjin, Sun, Li-Xian, Xu, Fen
Format: Article
Language:English
Subjects:
Biosensor
Direct electron transfer
Electrocatalysis
Electrodes
Enzymes
Flowerlike ZnO
Gold nanoparticles
Horseradish peroixdase
Nanocomposites
Nanomaterials
Nanostructure
Peroxidase
Silver
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We developed a new flowerlike ZnO–gold nanoparticles (GNPs)–Nafion nanocomposite which can promote the direct electron transfer of horseradish peroxidase (HRP) immobilized in the film effectively. The cyclic voltammetric results show that HRP entrapped in the composite could undergo a direct quasi-reversible electrochemical reaction with a formal potential ( E 0′) of −0.32 V (versus Ag/AgCl) in phosphate buffer solution (PBS). The flowerlike ZnO and GNPs show synergistic effect and the ZnO–GNPs–Nafion–HRP modified GC electrode gives an enhanced electrocatalytic activity towards the reduction of hydrogen peroxide (H 2O 2). The calculated apparent Michaelis–Menten constant ( K m app ) is 1.76 mM, which is much lower than that reported, indicating a high catalytic activity of HRP. The catalysis currents increase linearly to the H 2O 2 concentration in a wide range of 1.5 × 10 −5 to 1.1 × 10 −3 M, with a correlation coefficient of 0.998. The detection limit is 9.0 × 10 −6 M (at the ratio of signal to noise, S/N = 3), demonstrating that the formed film provides a favorable microenvironment for the enzyme to retain its activity. Moreover, the modified electrode displays rapid response to H 2O 2 and possesses good stability and reproducibility.
ISSN:0925-4005
1873-3077
DOI:10.1016/j.snb.2008.10.058