Direct electrochemistry and enzymatic activity of hemoglobin in positively charged colloid Au nanoparticles and hemoglobin layer-by-layer self-assembly films

作者：Ruo Yuan^*; ShuRui Cao; YaQin Chai; FengXian Gao; Oing Zhao; MingYu Tang; ZhongQiang Tong; Yi Xie

来源：Science in China Series B-Chemistry, 2007, 50(5): 620-628.

DOI：10.1007/S11426-007-0045-5

• positively charged colloid-Au nanoparticles (nano-Au circle plus)
• hemoglobin
• catalyze
• hydrogen peroxide

Alternate adsorption of positively charged colloid-Au nanoparticles (nano-Au-circle plus) and negatively charged hemoglobin (Hb) on L-cysteine (L-cys) modified gold electrode resulted in the assembly of {Hb/nano-Au-circle plus}(n) layer-by-layer films/L-cys modified gold electrode. The nano-Au-circle plus was characterized by transmission electron micrograph (TEM) and microelectrophoresis. The modified electrode interface morphology was characterized by electrochemical impedance spectroscopy (EIS), atomic force microscopy (AFM), cyclic voltammograms (CV) and chronoamperometry. Direct electron transfer between hemoglobin and gold electrodes was studied, and the apparent Michaelis-Menten constant (k(m)(app)) of the modified electrode was evaluated to be 0.10 mmol.L-1. Moreover, the higher activity of proteins in the nano-Au-circle plus films could be retained compared with the electropolymerization membrane, since the proteins in nano-Au-circle plus films retained their near-native structure. Direct electron transfer between hemoglobin and electrode and electrochemically catalyzed reduction of hydrogen peroxide on a modified electrode was studied, and the linear range was from 2.1 x 10(-8) to 1.2 x 10(-3) mol.L-1 (r=0.994) with a detection limit of 1.1 x 10(-8) mol-L-1 H2O2.

• 出版日期2007-10
• 单位西南大学