Department of Electrical and Computer Engineering, University of Missouri, Columbia, MO, USA.
Department Veterinary Pathobiology, University of Missouri, Columbia, MO, USA.
Electrophoresis. 2019 Feb;40(4):508-520. doi: 10.1002/elps.201800405. Epub 2019 Jan 4.
A MEMS-based impedance biosensor was designed, fabricated, and tested to effectively detect the presence of bacterial cells including E. coli O157:H7 and Salmonella typhimurium in raw chicken products using detection region made of multiple interdigitated electrode arrays. A positive dielectrophoresis based focusing electrode was used in order to focus and concentrate the bacterial cells at the centerline of the fluidic microchannel and direct them toward the detection microchannel. The biosensor was fabricated using surface micromachining technology on a glass substrate. The results demonstrate that the device can detect Salmonella with concentrations as low as 10 cells/mL in less than 1 h. The device sensitivity was improved by the addition of the focusing electrodes, which increased the signal response by a factor between 6 and 18 times higher than without the use of the focusing electrodes. The biosensor is selective and can detect other types of pathogen by changing the type of the antibody immobilized on the detection electrodes. The device was able to differentiate live from dead bacteria.
设计、制造和测试了一种基于 MEMS 的阻抗生物传感器，该传感器使用由多个叉指电极阵列制成的检测区域，可有效检测生鸡肉产品中包括大肠杆菌 O157:H7 和鼠伤寒沙门氏菌在内的细菌细胞的存在。采用基于正介电泳的聚焦电极将细菌细胞聚焦和集中在流道的中心线处，并引导它们进入检测微通道。该生物传感器是在玻璃衬底上使用表面微加工技术制造的。结果表明，该装置可以在不到 1 小时的时间内检测到浓度低至 10 个细胞/mL 的沙门氏菌。通过添加聚焦电极提高了器件的灵敏度，与不使用聚焦电极相比，信号响应提高了 6 到 18 倍。该生物传感器具有选择性，可以通过改变固定在检测电极上的抗体类型来检测其他类型的病原体。该装置能够区分活菌和死菌。
