Abstract

Single Cell and Microparticle Sensing with Microwave Sensor

Uzay Tefek, Graduate Student, Bilkent University

Real-time, rapid and accurate analysis of cells and microparticles is an important feature in biological and environmental sensing applications. In this study, we investigated whether the difference in dielectric properties of particles and cells in a solution passing through microfluidic could be detected and characterized by using a microwave sensor. With this system, we were able to use the dielectric signature of the analytes to distinguish different analyte particles (mammalian cells, different microplastics) from each other. To probe the internal structure of materials and avoid Debye screening, we worked at the microwave band using resonant sensors probed by a custom circuitry. Different entities, such as MDA-231 cells, and microplastic particles with different compositions and sizes were passed through the microchannel, and the signals they induced on the microwave sensors were matched with their optical images. By plotting the optical size vs. the microwave signals, it was observed that data for each particle class, clustered at a unique position in the sensing space, providing both size and material classification capability. The approach presented here opens up a path for label-free material classification and size detection in microfluidic systems.