A Microfluidic Impedance Cytometer for Accurate Detection and Counting of Circulating Tumor Cells by Simultaneous Mechanical and Electrical Sensing

Microfluidic Impedance Cytometry (MIC) is an advanced approach for single-cell analysis, harnessing microfluidic technology and impedance-based principles, particularly applicable in cancer diagnostics based on circulating tumor cells (CTCs). However, only relying on one dimensional information from electrical sensing poses challenges when detecting smaller CTCs that exhibit comparable sizes to white blood cells. To address this issue, we propose a microfluidic impedance cytometer featuring custom-designed circuits, electrodes, and a microfluidic chip with constriction channel. This system concurrently extracts both mechanical and electrical properties from processed electrical signals, overcoming the obstacle posed by the intrinsic link between impedance signals and cell sizes. Our system was tested with A549 lung cancer cells, white blood cells, and red blood cells, demonstrating the ability to differentiate cells of similar sizes within the blood sample and accurate cell couting capabilities. This approach shows promise for early cancer detection and monitoring treatment efficacy.