Cytometry with Electrochemical Impedance Spectroscopy

Abstract

Flow cytometry is a key methodology to identify, classify, and quantify cells for diagnostics, which is particularly important in liquid biopsy to identify rare cells for early cancer diagnostics. This project will investigate miniaturized, low-cost technology to detect and classify cells based on the different impedance spectra that arise due to their unique morphologies. We aim to design a micro-scale device that measures the impedance spectra of cells as they flow through, therefore identifying the type of cell. This can replace complex and expensive optical-based flow cytometers with point-of-care handheld diagnostics devices. In particular, we find impedance thresholds for polystyrene beads in an AC electric field, allowing us to classify them according to size based purely on their impedance spectra—a functionality that can be incorporated into the existing impedance sensing chip designed by the Sengupta lab. We also address the issues of channel clogging, DC offset, and low-frequency noise currently experienced by the chip. This research is part of an overall goal to develop a system that interfaces the microfluidic channel and sensing chip together with an FPGA for more sophisticated impedance measurements. This project requires knowledge in electrical, computer, and biological engineering.