A multifunctional micro-fluidic system for dielectrophoretic concentration coupled with immuno-capture of low numbers of Listeria monocytogenes
A multifunctional micro-fluidic system for dielectrophoretic concentration coupled with immuno-capture of low numbers of Listeria monocytogenes
复制标题
DOI：
10.1039/b607061m
复制
发表时间：
2006-01-01
期刊：
影响因子：
6.1
通讯作者：
Bashir, Rashid
中科院分区：
文献类型：
--
作者：
Yang, Liju;Banada, Padmapriya P.;Bashir, Rashid
在这项研究中，我们展示了一种多功能的微流控系统，包括使用介电泳法(DEP)浓缩细菌和使用抗体识别选择性捕获细菌，从而实现了对细菌细胞的高捕获效率。该器件由平面硅衬底上的氧化物覆盖的交指电极阵列和类似16微米高和260微米宽的PDMS盖内的微通道组成。为了从样品中选择性捕获李斯特菌，通道表面被生物素标记的BSA链霉亲和素-生物素标记的单抗夹心结构功能化。用阳性DEP(20V-pp和1 MHz)浓缩液体中的细菌细胞。当进样量为5-20亩L时，当流速为0.2亩L min(-1)时，DEP可连续收集近90%的细胞进入10(2)-10(3)的微通道，而当流速为0.6亩L min(-1)时，DEP的捕集效率降至65%左右。正DEP将细胞吸引到电场梯度最高的电极边缘。DEP浓缩的细胞被固定在通道表面的抗体捕获，效率为18%~27%，细菌细胞数从10(1)到10(3)个。我们的实验发现，DEP操作并没有对细菌细胞造成任何不可逆转的细胞活力损害。此外，在DEP暴露后，细胞膜上的抗原(C11E9单抗的抗原)表达增加。
In this study, we demonstrated a micro-fluidic system with multiple functions, including concentration of bacteria using dielectrophoresis (DEP) and selective capture using antibody recognition, resulting in a high capture efficiency of bacterial cells. The device consisted of an array of oxide covered interdigitated electrodes on a flat silicon substrate and a similar to 16 mu m high and similar to 260 mu m wide micro-channel within a PDMS cover. For selective capture of Listeria monocytogenes from the samples, the channel surface was functionalized with a biotinylated BSA streptavidin-biotinylated monoclonal antibody sandwich structure. Positive DEP (at 20 V-pp and 1 MHz) was used to concentrate bacterial cells from the fluid flow. DEP could collect similar to 90% of the cells in a continuous flow at a flow rate of 0.2 mu l min(-1) into the micro-channel with concentration factors between 10(2)-10(3), in sample volumes of 5-20 mu l. A high flow rate of 0.6 mu l min(-1) reduced the DEP capture efficiency to similar to 65%. Positive DEP attracts cells to the edges of the electrodes where the field gradient is the highest. Cells concentrated by DEP were captured by the antibodies immobilized on the channel surface with efficiencies of 18 to 27% with bacterial cell numbers ranging from 10(1) to 10(3) cells. It was found that DEP operation in our experiments did not cause any irreversible damage to bacterial cells in terms of cell viability. In addition, increased antigen expression ( antigens to C11E9 monoclonal antibody) on cell membranes was observed following the exposure to DEP.