The Escherichia coli O157:H7 DNA detection on a gold nanoparticle-enhanced piezoelectric biosensor  

作　　者：WANG LiJiang WEI QingShan WU ChunSheng HU ZhaoYing JI Jian WANG Ping 

机构地区：[1]Biosensor National Special Laboratory and Key Laboratory of Biomedical Engineering of Ministry of Education, Department of Biomedical Engineering, Zhejiang University, Hangzhou 310027, China [2]Key Laboratory of Macromolecule Synthesis and Functionalization of Ministry of Education, Zhejiang University, Hangzhou 310027 China

出　　处：《Chinese Science Bulletin》2008年第8期1175-1184,共10页

基　　金：the National Natural Science Foundation of China (Grant No. 30570492);the Project of State Key Laboratory of Transducer Technology of China (Grant No. SKT0403);the Zhejiang Province Natural Science Foundation of China (Grant No. R205505)

摘　　要：This paper presents development of a quartz crystal microbalance (QCM) biosensor for real-time de- tection of E. coli O157:H7 DNA based on nanogold particles amplification. Many inner Au nanoparticles were immobilized onto the thioled surface of the Au electrode, then more specific thiolated sin- gle-stranded DNA (ssDNA) probes could be fixed through Au-SH bonding. The hybridization was in- duced by exposing the ssDNA probe to the complementary target DNA of E. coli O157:H7 gene eaeA, then resulted in a mass change and corresponding frequency shifts ( △f ) of the QCM. The outer avidin-coated Au nanoparticles could combine with the target DNA to increase the mass. The electro- chemical techniques, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were adopted to manifest and character each step. The target DNA corresponding to 2.0×103 colony forming unit (CFU)/mL E. coli O157:H7 cells can be detected by this biosensor, so it is practical to develop a sensitive and effective QCM biosensor for pathogenic bacteria detection based on specific DNA analy- sis. The piezoelectric biosensing system has potential for further applications, such as food safety and environment monitoring, and this approach lays the groundwork for incorporating the method into an integrated system for in-field bacteria detection.This paper presents development of a quartz crystal microbalance （QCM） biosensor for real-time detection of E. coil O157：H7 DNA based on nanogold particles amplification. Many inner Au nanoparticles were immobilized onto the thioled surface of the Au electrode, then more specific thiolated sin- gle-stranded DNA （ssDNA） probes could be fixed through Au-SH bonding. The hybridization was induced by exposing the ssDNA probe to the complementary target DNA of E. coli O157：H7 gene eaeA, then resulted in a mass change and corresponding frequency shifts （ △f ） of the QCM. The outer avidin-coated Au nanoparticles could combine with the target DNA to increase the mass. The electrochemical techniques, cyclic voltammetry （CV） and electrochemical impedance spectroscopy （EIS） were adopted to manifest and character each step. The target DNA corresponding to 2.0×10^3 colony forming unit （CFU）/mL E. coil O157：H7 cells can be detected by this biosensor, so it is practical to develop a sensitive and effective QCM biosensor for pathogenic bacteria detection based on specific DNA analysis. The piezoelectric biosensing system has potential for further applications, such as food safety and environment monitoring, and this approach lays the groundwork for incorporating the method into an integrated system for in-field bacteria detection.

关 键 词：压电生物受感器 黄金纳米颗粒 DNA 大肠埃希氏菌 

分 类 号：R3[医药卫生—基础医学]