title: Electrochemical Impedance Immunosensor Based on Self-Assembled Monolayers for Rapid Detection of Escherichia coli O157:H7 with Signal Amplification Using Lectin.
abstract: Escherichia coli O157:H7 is a predominant foodborne pathogen with severe pathogenicity, leading to increasing attention given to rapid and sensitive detection. Herein, we propose an impedance biosensor using new kinds of screen-printed interdigitated microelectrodes (SPIMs) and wheat germ agglutinin (WGA) for signal amplification to detect E. coli O157:H7 with high sensitivity and time-efficiency. The SPIMs integrate the high sensitivity and short response time of the interdigitated electrodes and the low cost of the screen-printed electrodes. Self-assembling of bi-functional 3-dithiobis-(sulfosuccinimidyl-propionate) (DTSP) on the SPIMs was investigated and was proved to be able to improve adsorption quantity and stability of biomaterials. WGA was further adopted to enhance the signal taking advantage of the abundant lectin-binding sites on the bacteria surface. The immunosensor exhibited a detection limit of 102 cfu·mL(-1), with a linear detection range from 10(2) to 10(7) cfu·mL(-1) (r2 = 0.98). The total detection time was less than 1 h, showing its comparable sensitivity and rapid response. Furthermore, the low cost of one SPIM significantly reduced the detection cost of the biosensor. The biosensor may have great promise in food safety analysis and lead to a portable biosensing system for routine monitoring of foodborne pathogens.
authors.affiliation: College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China. lizhanming1018@126.com.
authors.forename: Zhanming
authors.initials: Z
authors.lastname: Li
authors.affiliation: College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China. yingchunfu@126.com.
authors.forename: Yingchun
authors.initials: Y
authors.lastname: Fu
authors.affiliation: College of Animal Science, Zhejiang University, Hangzhou 310058, China. whfang@zju.deu.cn.
authors.forename: Weihuan
authors.initials: W
authors.lastname: Fang
authors.affiliation: College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China. yanbinli@zju.edu.cn.|Department of Biological & Agricultural Engineering, University of Arkansas, Fayetteville, AR 72701, USA. yanbinli@zju.edu.cn.
authors.forename: Yanbin
authors.initials: Y
authors.lastname: Li
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry; D015374:Biosensing Techniques / Q000295:instrumentation*; D003198:Computer Simulation; D017097:Electric Impedance; D055664:Electrochemical Techniques / Q000295:instrumentation*; D019453:Escherichia coli O157 / Q000276:immunology* / Q000302:isolation & purification*; D008839:Microelectrodes; D012815:Signal Processing, Computer-Assisted; D013388:Succinimides / Q000737:chemistry; D014909:Wheat Germ Agglutinins / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D013388:Succinimides; D014909:Wheat Germ Agglutinins; C035759:3,3'-dithiobis(sulfosuccinimidyl propionate)
keywords: Escherichia coli O157:H7; ·impedance immunosensor; ·lectin; ·screen-printed interdigitated microelectrode