A portable single-cell analysis system integrating hydrodynamic trapping with broadband impedance spectroscopy

In this paper, we present a portable single-cell analysis system with the hydrodynamic cell trapping and the broadband electrical impedance spectroscopy (EIS). Using the least flow resistance path principle, the hydrodynamic cell trapping in serpentine arrays can be carried out in a deterministic and automatic manner without the assistance of any external fields. The experimental results show that a cell trap rate of higher than 95% can be easily achieved in our cell trapping microdevices. Using the maximum length sequences (MLS) technique, our home-made EIS is capable of measuring the impedance spectrum ranging from 1.953 kHz to 1 MHz in approximately 0.5 ms. Finally, on the basis of the developed single-cell analysis system, we precisely monitor the trapping process of human breast tumor cells (MCF-7 cells) according to the changes of electrical impedance. The MCF-7 cells with different trapping conditions or sizes can also be clearly distinguished through the impedance signals. Our portable single-cell analysis system may provide a promising tool to monitor single cells for long periods of time or to discriminate cell types.