Highly sensitive organic electrochemical transistor for detection of stress-induced cation leakage from plant cells

Stress-induced ionic leakage plays a key role in understanding plant physiology. The ability of the plant cell membrane to withstand environmental stress factors can be gauged through monitoring of cation (especially K+) leakage. In this study, we have developed a PEDOT:PSS polymer-based organic electrochemical transistor (OECT) for detecting the discharged cations from Tephrosia purpurea leaf samples under hyperthermal stress. The test leaf samples were exposed to different heat stress environments and the discharged ions from the stress-treated leaf samples were collected in DI water through incubation. The cation detection was then performed via depletion mode operation of OECTs. Our analysis revealed that the OECTs are highly sensitive toward cation detection under low operating voltage (<1 V). In addition, OECTs are sensitive even at cation concentrations below 5 ppm. The present approach of cation detection through OECT provides a new way of understanding plant physiology.