Filippo Bonafè1,Francesco Decataldo1,Isabella Zironi1,Daniel Remondini1,Tobias Cramer1,Beatrice Fraboni1
University of Bologna1
Filippo Bonafè1,Francesco Decataldo1,Isabella Zironi1,Daniel Remondini1,Tobias Cramer1,Beatrice Fraboni1
University of Bologna1
Research on electrolyte-gated and organic electrochemical transistor (OECT) architectures is motivated by the prospect of a highly biocompatible interface capable of amplifying bioelectronic signals at the site of detection. Despite many demonstrations in these directions, a quantitative model for OECTs as impedance biosensors is still lacking. We overcome this issue by introducing a model experiment where we simulate the detection of a single cell by the impedance sensing of a dielectric microparticle. The highly reproducible experiment allows us to study the impact of transistor geometry and operation conditions on device sensitivity. With the data we rationalize a mathematical model that provides clear guidelines for the optimization of OECTs as single cell sensors, and we verify the quantitative predictions in an in-vitro experiment. In the optimized geometry, the OECT-based impedance sensor allows to record single cell adhesion and detachment transients, showing a maximum gain of 20.2±0.9 dB with respect to a single electrode-based impedance sensor.<br/><br/><b>References:</b><br/>Bonafè, F. <i>et al.</i> AC amplification gain in organic electrochemical transistors for impedance-based single cell sensors. <i>Nat Commun</i> <b>13</b>, 5423 (2022).