Dielectric spectroscopy (DS) is a promising cell screening method used for diagnostic and drug discovery purposes. The primary challenge of using DS in physiological buffers is the electrode polarization (EP) that overwhelms the impedance signal within a large frequency range. These effects are further amplified with the miniaturization of the measurement electrodes. This thesis presents a microfluidic system and the associated equivalent circuit models for real-time measurements of cell membrane capacitance and cytoplasm resistance in physiological buffers. The current device captures hundreds of biological cells in individual microwells through gravitational settling and measures the system’s impedance using microelectrodes covered with dendritic gold nanostructures. First, stable cell membrane capacitance and cytoplasm resistance measurements in the device for over 15 minutes were demonstrated. Then the effects of an ion-channel blocker drug, Amiodarone, on the membrane capacitance and cytoplasm resistance of PC-3 Prostate cancer cells were investigated as a function of the drug concentration for 1,000 seconds. Control experiments using glucose and aspirin were also conducted. Overall, real-time measurements of cell response to different drug doses in physiological buffers were successfully carried out.
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Bakhtiari, Shide, "A Microfluidic Dielectric Spectroscopy System for Characterization of Biological Cells in Physiological Media" (2022). Mechanical Engineering Research Theses and Dissertations. 40.
Available for download on Tuesday, May 18, 2027