Key Lab of Corrosion Science, Shandong Province, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
Talanta. 2009 Nov 15;80(1):218-23. doi: 10.1016/j.talanta.2009.06.057. Epub 2009 Jul 3.
An impedimetric immunosensor was fabricated for rapid and non-labeled detection of sulfate-reducing bacteria, Desulforibrio caledoiensis (SRB) by immobilizing lectin-Concanavalin A using an agglutination assay. The immobilization of lectin was conducted using amine coupling on the surface of a gold (Au) electrode assembled with 11-Mercaptoundecanoic acid. Electrochemical impedance spectroscopy (EIS) was used to verify the stepwise assembly of the sensor system. The work conditions of the impedimetric immunosensor, such as pH of the buffer solutions and the incubation time of lectin, were optimized. Faradic impedance spectra for charge transfer for the redox probe Fe(CN)(6)(3-/4-)were measured to determine SRB concentrations. The diameter of the Nyquist diagram that is equal to the charge-transfer resistance (R(ct)) increased with increasing SRB concentration. A linear relationship between R(ct) and SRB concentration was obtained in SRB concentration range of 1.8 to 1.8 x 10(7)cfu/ml. The variation of the SRB population during the growth process was also monitored using the impedimetric immunosensor. This approach has great potential for simple, low-cost, and time-saving monitoring of microbial populations.
一种基于凝集反应的无标记电化学生物传感器，通过固定凝集素-刀豆球蛋白 A 被用于快速检测硫酸盐还原菌（Desulforibrio caledoiensis）。凝集素通过胺偶联固定在巯基十一酸自组装的金电极表面。电化学阻抗谱（EIS）被用来验证传感器系统的逐步组装。优化了生物传感器的工作条件，如缓冲溶液的 pH 值和凝集素的孵育时间。通过测量电化学探针 Fe(CN)(6)(3-/4-)的法拉第阻抗谱来确定硫酸盐还原菌的浓度。奈奎斯特图的直径（即电子转移电阻 R(ct)）随硫酸盐还原菌浓度的增加而增大。在 1.8 到 1.8 x 10(7)cfu/ml 的硫酸盐还原菌浓度范围内，R(ct)与硫酸盐还原菌浓度之间存在线性关系。还使用电化学生物传感器监测了硫酸盐还原菌生长过程中的种群变化。这种方法具有简单、低成本和节省时间的特点，有望用于微生物种群的监测。
