Embedded silver PDMS electrodes for single cell electrical impedance spectroscopy

Abstract

This paper presents a microfluidic device with wide channels and embedded AgPDMS electrodes for measuring the electrical properties of single cells. The work demonstrates the feasibility of using a large channel design and embedded electrodes for impedance spectroscopy to circumvent issues such as channel clogging and limited device re-usability. AgPDMS electrodes were formed on channel sidewalls for impedance detection and cell electrical properties measurement. Equivalent circuit models were used to interpret multi-frequency impedance data to quantify each cell's cytoplasm conductivity and specific membrane capacitance. T24 cells were tested to validate the microfluidic system and modeling results. Comparisons were then made by measuring two leukemia cell lines (AML-2 and HL-60) which were found to have different cytoplasm conductivity values (0.29 ± 0.15 S m−1 versus 0.47 ± 0.20 S m−1) and specific membrane capacitance values (41 ± 25 mF m−2 versus 55 ± 26 mF m−2) when the cells were flown through the wide channel and measured by the AgPDMS electrodes.