Doping Organic Thin Film Transistor by Valinomycin for Detecting Ion of Potassium

This work demonstrates an alternative organic semiconductor-based ion sensor design, and effortless that avoids the use of membranes with sensitizer and separate compartments, unlike previous architecture. Instead, we simply dope an organic semiconductor with a specific sensitizer ionophore called valinomycin into a polythiophene casting solution that is used to manufacture organic thin-film transistors. Resulting OTFTs display near-Nernstian ion sensitivity of their threshold voltage within different potassium ion concentrations. The Nernstian ion sensitivity is 52±2 mV/dec, and the limit of detection is 15±5 μM.