Determination of carcinoembryonic antigen using a novel amperometric enzyme-electrode based on layer-by-layer assembly of gold nanoparticles and thionine  

作　　者：YUAN Ruo ZHUO Ying CHAI YaQin ZHANG Ying SUN AiLi 

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1期97-104,共8页中国科学（化学英文版）

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

摘　　要：Electrochemical sensing of carcinoembryonic antigen(CEA)on a gold electrode modified by the se- quential incorporation of the mediator,thionine(Thi),and gold nanoparticles(nano-Au),through co- valent linkage and electrostatic interactions onto a self-assembled monolayer configuration is de- scribed in this paper.The enzyme,horseradish peroxidase(HRP),was employed to block the possible remaining active sites of the nano-Au monolayer,avoid the non-specific adsorption,instead of bovine serum albumin(BSA),and amplify the response of the antigen-antibody reaction.Electrochemical ex- periments indicated highly efficient electron transfer by the imbedded Thi mediator and adsorbed nano-Au.The HRP kept its activity after immobilization,and the studied electrode showed sensitive response to CEA and high stability during a long period of storage.The working range for the system was 2.5 to 80.0 ng/mL with a detection limit of 0.90 ng/mL.The model membrane system in this work is a potential biosensor for mimicking the other immunosensor and enzyme sensor.Electrochemical sensing of carcinoembryonic antigen (CEA) on a gold electrode modified by the sequential incorporation of the mediator, thionine (Thi), and gold nanoparticles (nano-Au), through covalent linkage and electrostatic interactions onto a self-assembled monolayer configuration is described in this paper. The enzyme, horseradish peroxidase (HRP), was employed to block the possible remaining active sites of the nano-Au monolayer, avoid the non-specific adsorption, instead of bovine serum albumin (BSA), and amplify the response of the antigen-antibody reaction. Electrochemical experiments indicated highly efficient electron transfer by the imbedded Thi mediator and adsorbed nano-Au. The HRP kept its activity after immobilization, and the studied electrode showed sensitive response to CEA and high stability during a long period of storage. The working range for the system was 2.5 to 80.0 ng/mL with a detection limit of 0.90 ng/mL. The model membrane system in this work is a potential biosensor for mimicking the other immunosensor and enzyme sensor.

关 键 词：IMMUNOSENSOR gold nanoparticles(nano-Au) thionine(Thi) carcinoembryonic antigen(CEA) HORSERADISH peroxidase(HRP) layer-by-layer(LBL) 

分 类 号：R446.6[医药卫生—诊断学]