Direct Electrochemistry and Electrocatalysis of Hemoglobin/ZnO‐Chitosan/nano‐Au Modified Glassy Carbon Electrode

Abstract

The highly efficient H 2 O 2 biosensor was fabricated on the basis of the complex films of hemoglobin (Hb), nano ZnO, chitosan (CHIT) dispersed solution and nano Au immobilized on glassy carbon electrode (GCE). Biocompatible ZnO-CHIT composition provided a suitable microenvironment to keep Hb bioactivity (Michaelis-Menten constant of 0.075 mmol L À1). The presence of nano Au in matrix could effectively enhance electron transfer between Hb and electrode. The electrochemical behaviors and effects of solution pH values were carefully examined in this paper. The (ZnO-CHIT)-Au-Hb/GCE demonstrated excellently electrocatalytical ability for H 2 O 2 . This biosensor had a fast response to H 2 O 2 less than 4 s and excellent linear relationships were obtained in the concentration range from1.94 Â 10 À7 to 1.73 Â 10 À3 mol L À1 with the detection limit of 9.7 Â 10 À8 mol L À1 (S/N ¼ 3) under the optimum conditions. Moreover, the stability and reproducibility of this biosensor were evaluated with satisfactory results.

Enzyme-based Electrochemical Biosensors

“…Biocompatible nanogold could further allow HRP to be immobilized with well-remained bioactivity in addition to increased loading amount. The prepared biosensor can achieve sensitive electrochemical response to H 2 O 2 at a potential of -0.2 V. Similar composites for enzyme immobilization was reported by Duan et al (Duan et al, 2008), but the composites were mixed by the solutions of ZnO/chitosan, Hb and gold. The as-prepared biosensor has a fast response to H 2 O 2 within 4 s and a detection limit of 0.097 µM.…”

Nanostructured Metal Oxides Based Enzymatic Electrochemical Biosensors

“…The developed biosensor displayed good performance for the detection of H 2 O 2 and NaNO 2 with a wide linear range of 1-410 and 10-2700 μM, respectively. Duan et al, (2008) prepared complex film containing of hemoglobin, nano ZnO, chitosan and nano Au to immobilized onto glassy carbon electrode for H 2 O 2 sensing. Chitosan improved the film forming ability to the substrate and presence of gold nanoparticles enhanced electrocatalytic performance such as reproducible high sensitivity, linearity (1.94 x 10 -7 -1.73 x 10 -3 mol L -1 ) and detection limit (9.7x 10 -8 mol L -1 ) of the fabricated bioelectrode.…”

Hydrogen peroxide biosensor based on poly (vinyl alcohol)/ZnO nanorods composite films

“…Sun et al reported electrochemistry of hemoglobin entrapped in a Nafion/nano-ZnO film on carbon ionic liquid electrode [28]. Duan and his co-workers developed a hydrogen peroxide biosensor based on the complex films of hemoglobin (Hb), nano ZnO, chitosan (CHIT) dispersed solution and nano Au immobilized on glassy carbon electrode (GCE) [29]. Kong [30].…”