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

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 −1 ). 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 from1.94×10 −7 to 1.73×10 −3 mol L −1 with the detection limit of 9.7×10 −8 mol L −1 ( S / N =3) under the optimum conditions. Moreover, the stability and reproducibility of this biosensor were evaluated with satisfactory results.