Organic Electrochemical Transistors: Smart Devices for Real-Time Monitoring of Cellular Vitality

Current technologies to monitor formation and disruption in in vitro cell cultures are based either on optical techniques or on electrical impedance/resistance measurement, which often rely on cumbersome and time-consuming measurements and data analyses. In this paper, poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS)-based organic electrochemical transistors (OECTs) are proposed with channel areas specifically designed and dimensioned as fast and real-time monitoring devices for a large variety of cell lines, with a broad range of tissue resistance. In particular, it is investigated how and why two device configurations provide a different response to leaky-barrier (NIH-3T3) and strong-barrier (CaCo-2) cell lines growth and detachment, achieving a continuous monitoring also for leaky-barrier cell layer growth and detachment. Data are collected using the transistor dynamic behavior to a DC potential pulse on the gate, providing an excellent time resolution and thus enhancing the amount of information that can be collected for fast biological processes (<5 s).