Microscale electronic detection of bacterial metabolism
Microscale electronic detection of bacterial metabolism
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DOI：
10.1016/s0925-4005(02)00175-2
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发表时间：
2002-09-20
影响因子：
8.4
通讯作者：
Bhunia, AK
中科院分区：
文献类型：
--
作者：
Gómez, R;Bashir, R;Bhunia, AK
在本文中，我们提出了一种基于微尺度阻抗的技术来检测几种活细菌细胞的代谢活性。基于阻抗的检测依赖于测量与培养细菌的液体接触的两个电极的交流阻抗变化，这种变化是由代谢细胞释放离子引起的。理论上，如果细胞被限制在纳升量级的体积内，快速检测少量活细胞（1-10）是可能的。一种微流控生物芯片原型已经被制造出来来探索这种技术，它由蚀刻在晶体硅衬底上的通道和腔室网络组成。在生物芯片的5.27 nl腔室中，在100 Hz和1 MHz之间的频率下，使用交叉指状铂电极测量细菌悬浮液的复杂阻抗。片外孵育2小时后，在低电导率缓冲液中悬浮的活细胞的最小数量可以很容易地与相同数量的热杀伤细胞区分，在5.27 nl的腔室中，活细胞的数量约为100个李斯特菌、200个单核细胞增生细胞和40个大肠杆菌。100个左右的innocua细胞悬浮在Luria-Bertani （LB）肉汤中，产生的信号明显高于相同数量的热灭活细胞，甚至相差5-20个细胞。据我们所知，这是首次展示了基于微阻抗的细菌代谢检测。(C) 2002 Elsevier Science B.V.版权所有
In this paper, we present a microscale impedance-based technique for detecting the metabolic activity of a few live bacterial cells. Impedance-based detection relies on measuring changes in the ac impedance of two electrodes in contact with a liquid where the bacteria are cultured, caused by the release of ionic species by metabolizing cells. Rapid detection of a few live cells (1-10) is, in theory, possible if the cells are confined into a volume on the order of nanoliters. A microfluidic biochip prototype has been fabricated to explore this technique, consisting of a network of channels and chambers etched in a crystalline silicon substrate. The complex impedance of bacterial suspensions is measured with interdigitated platinum electrodes in a 5.27 nl chamber in the biochip at frequencies between 100 Hz and 1 MHz. After 2 h of off-chip incubation, the minimum number of live cells suspended in a low conductivity buffer that could be easily distinguished from the same number of heat-killed cells was on the order of 100 Listeria innocua, 200 L monocytogenes, and 40 Escherichia coli cells, confined into the 5.27 nl chamber. A number on the order of 100 live L. innocua cells suspended in Luria-Bertani (LB) broth produced a significantly higher signal than the same number of heat-killed cells, and a difference is evident even down to similar to5-20 cells. To the best of our knowledge, this is the first demonstration of microscale impedance-based detection of bacterial metabolism. (C) 2002 Elsevier Science B.V. All rights reserved.