Guntupalli R, Lakshmanan R S, Hu J, Huang T S, Barbaree J M, Vodyanoy V, Chin B A
Materials Research and Education Center, Auburn University, Auburn, AL 36849, USA.
J Microbiol Methods. 2007 Jul;70(1):112-8. doi: 10.1016/j.mimet.2007.04.001. Epub 2007 Apr 11.
In this article, we report the results of an investigation into the performance of a wireless, magnetoelastic biosensor designed to selectively detect Salmonella typhimurium in a mixed microbial population. The Langmuir-Blodgett (LB) monolayer technique was employed for antibody (specific to Salmonella sp.) immobilization on rectangular shaped strip magnetoelastic sensors (2 x 0.4 x 0.015 mm). Bacterial binding to the antibody on the sensor surface changes the resonance parameters, and these changes were quantified as a shift in the sensor's resonance frequency. Response of the sensors to increasing concentrations (5 x 10(1) to 5 x 10(8) cfu/ml) of S. typhimurium in a mixture of extraneous foodborne pathogens (Escherichia coli O157:H7 and Listeria monocytogenes) was studied. A detection limit of 5 x 10(3) cfu/ml and a sensitivity of 139 Hz/decade were observed for the 2 x 0.4 x 0.015 mm sensors. Binding kinetics studies have shown that the dissociation constant (K(d)) and the binding valencies for water samples spiked with S. typhimurium was 435 cfu/ml and 2.33 respectively. The presence of extraneous microorganisms in the mixture did not produce an appreciable change in the biosensor's dose response behavior.
在本文中，我们报告了一项关于无线磁弹性生物传感器性能的调查结果，该传感器旨在选择性检测混合微生物群体中的鼠伤寒沙门氏菌。采用朗缪尔-布洛杰特（LB）单层技术将抗体（对沙门氏菌属具有特异性）固定在矩形带状磁弹性传感器（2×0.4×0.015毫米）上。细菌与传感器表面抗体的结合会改变共振参数，这些变化被量化为传感器共振频率的偏移。研究了传感器对在无关食源性病原体（大肠杆菌O157:H7和单核细胞增生李斯特菌）混合物中鼠伤寒沙门氏菌浓度增加（5×10¹至5×10⁸cfu/ml）的响应。对于2×0.4×0.015毫米的传感器，观察到检测限为5×10³cfu/ml，灵敏度为139Hz/十倍浓度变化。结合动力学研究表明，添加鼠伤寒沙门氏菌的水样的解离常数（K(d)）和结合价分别为435cfu/ml和2.33。混合物中无关微生物的存在并未使生物传感器的剂量响应行为产生明显变化。
