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

作　　者：YUAN Ruo CAO ShuRui CHAI YaQin GAO FengXian ZHAO Qing TANG MingYu TONG ZhongQiang XIE Yi 

机构地区：[1]Chongqing Key Laboratory of Analytical Chemistry,College of Chemistry and Chemical Engineering,Southwest University,Chongqing 400715,China

出　　处：《Science China Chemistry》2007年第5期620-628,共9页中国科学(化学英文版)

基　　金：Supported by the National Natural Science Foundation of China(Grant No.20675064);the Natural Science Foundation of Chongqing City,China(Grant Nos.CSTC-2004 BB4149,2005 BB4100);High Technology Project Foundation of Southwest University(Grant No.XSGX02)

摘　　要：Alternate adsorption of positively charged colloid-Au nanoparticles(nano-Au^(⊕))and negatively charged hemoglobin(Hb)on L-cysteine(L-cys)modified gold electrode resulted in the assembly of{Hb/nano-Au^(⊕)}n layer-by-layer films/L-cys modified gold electrode.The nano-Au^(⊕)was characterized by transmission electron micrograph(TEM)and microelectrophoresis.The modified electrode interface morphology was characterized by electrochemical impedance spectroscopy(EIS),atomic force mi-croscopy(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^(⊕)films could be retained compared with the electropolymerization membrane,since the pro-teins in nano-Au^(⊕)films retained their near-native structure.Direct electron transfer between hemoglo-bin and electrode and electrochemically catalyzed reduction of hydrogen peroxide on a modified elec-trode was studied,and the linear range was from 2.1×10^(-8)to 1.2×10^(-3)mol·L^(-1)(r=0.994)with a detection limit of 1.1×10^(-8)mol·L^(-1)H_(2)O_(2).

关 键 词：positively charged colloid-Au nanoparticles(nano-Au^(⊕)) HEMOGLOBIN CATALYZE hydrogen peroxide 

分 类 号：N[自然科学总论]