School of Materials Science and Engineering, Bengal Engineering and Science University Shibpur, Howrah 711103, India.
Biomed Microdevices. 2012 Oct;14(5):955-64. doi: 10.1007/s10544-012-9674-3.
This paper reports the design and fabrication of electrode microtraps for single cell trapping and impedance measurement. In this work, the microtrap electrodes of parallel and elliptical geometry have been fabricated by electroplating of gold electrodes of optimum thickness. This has enabled the formation of electrode traps without requiring any precision alignment between separate insulating traps like PDMS and the bottom gold electrodes. Further the improved uniformity of the electric field between the trapping electrodes as observed from COVENTORWARE simulation significantly reduces the effect of cell position inside the microwell on the electrical measurement unlike previous reports. This makes it possible to directly extract the equivalent cell parameters from the electrical measurement without introducing any correction factor corresponding to cell position. We have performed impedance spectroscopy with both the microwell electrode structures with single HeLa cell at two different positions of trapping. It has been observed that there is almost no change in the extracted values of cell resistance and capacitance for different positions within parallel electrodes and there is only 0.7 % and 0.85 % change in cell resistance and capacitance for the two positions within elliptical electrodes. Thus these microwell electrode structures can be used as an improved and a more convenient platform for single cell electrical characterization.
本文报道了用于单细胞捕获和阻抗测量的电极微阱的设计和制造。在这项工作中，通过最佳厚度的金电极电镀来制造具有平行和椭圆形几何形状的微阱电极。这使得能够形成电极阱，而不需要 PDMS 等单独的绝缘阱与底部金电极之间的任何精密对准。此外，与以前的报告相比，从 COVENTORWARE 模拟中观察到的捕获电极之间电场的均匀性得到了显著提高，这大大降低了细胞在微井内位置对电测量的影响。这使得可以直接从电测量中提取等效细胞参数，而无需引入与细胞位置相对应的任何校正因子。我们在具有单个 HeLa 细胞的两个不同捕获位置的微阱电极结构上进行了阻抗谱测量。观察到，在平行电极的不同位置，细胞电阻和电容的提取值几乎没有变化，而在椭圆形电极的两个位置，细胞电阻和电容仅变化 0.7%和 0.85%。因此，这些微阱电极结构可以用作单细胞电特性分析的改进和更方便的平台。
