Label-free detection of bacteria by electrochemical impedance spectroscopy: Comparison to surface plasmon resonance
Label-free detection of bacteria by electrochemical impedance spectroscopy: Comparison to surface plasmon resonance
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DOI：
10.1021/ac070085n
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发表时间：
2007-07-01
影响因子：
7.4
通讯作者：
Jaffrezic-Renault, Nicole
中科院分区：
文献类型：
--
作者：
Maalouf, Rita;Fournier-Wirth, Chantal;Jaffrezic-Renault, Nicole
细菌污染的低风险但已知的风险已成为输血传播疾病的最大残余威胁。使用非法拉第电化学阻抗谱(EIS)对细菌模型大肠杆菌进行无标记检测。生物素标记的多克隆抗E.Coli通过生物素-中性亲和素的相互作用连接到金电极上的混合自组装单分子膜(SAM)上。用表面等离子体共振(SPR)测定了一个抗体分子与3.6个中性亲和素分子的结合。SPR对大肠杆菌的检出限为10(7)cfu/m L。对大肠杆菌/抗E-E的阻抗奈奎斯特图进行建模。Coli/混合SAM/金电极用于提高E.Coli(整菌或裂解菌)的浓度，修饰的主要参数是极化电阻R-P。当细菌(完整或裂解)的对数浓度增加时，R-P呈S型变化。通过EIS检测，整个细菌的浓度为10cfu/m L，而裂解的大肠杆菌为10(3)cfu/m L。
The low but known risk of bacterial contamination has emerged as the greatest residual threat of transfusion-transmitted diseases. Label-free detection of a bacterial model, Escherichia coli, is performed using nonfaradic electrochemical impedance spectroscopy (EIS). Biotinylated polyclonal anti-E. coli is linked to a mixed self-assembled monolayer (SAM) on a gold electrode through a strong biotin-neutravidin interaction. The binding of one antibody molecule for 3.6 neutravidin molecules is determined using the surface plasmon resonance (SPR). The detection limit of E. coli found by SPR is 10(7) cfu/mL. After modeling the impedance Nyquist plot of E. coli/anti-E. coli/mixed SAM/gold electrode for increasing concentrations of E. coli (whole bacteria or lysed bacteria), the main parameter that is modified is the polarization resistance R-P. A sigmoid variation of R-P is observed when the log concentration of bacteria (whole or lysed) increases. A concentration of 10 cfu/mL whole bacteria is detected by EIS measurements while 10(3) cfu/mL is detected for lysed E. coli.