EDL Gated FET Biosensor Array for the Investigation of Ion Channels and Bioelectric Signals of Circulating Tumor Cells

Abstract

This paper demonstrates a novel methodology to analyze the bioelectric signals of cells in different test media using highly sensitive Electrical Double Layer (EDL) gated AlGaN/GaN HEMT (High Electron Mobility Transistor) biosensor array. Circulating Tumor Cells (CTCs) derived from Colorectal Cancer (CRC) were the target of this experiment. Previously, we had demonstrated that our sensor can detect and count the number of captured cells with up to single cell resolution. Thereafter, we further discovered that our sensor can be used in detecting important fundamental bioelectric signals of cell. We have demonstrated that our FET (Field Effect Transistor) biosensor can dynamically monitor the changes in transmembrane potential of cells induced by high concentrations of extracellular KCl, low and high extracellular divalent cation concentrations. Additionally, cadmium ions were used to block the calcium channels present in the cell demonstrating an interesting application of bioelectric signal study. Thus, we demonstrate that our sensing methodology can replace the conventional methods to study fundamental cellular mechanisms such as ion channel gating.