Integrated amplifier with complementary organic electrochemical transistors for high-sensitivity ion detection and real-time monitoring

Ions are fundamental biological regulators enabling the communication between cells, regulating metabolic and bioenergetic processing and playing a key role in pH regulation and hydration. The in-situ quantification of the ion concentration is gathering relevant interest in biomedical diagnostics and healthcare. State-of-art transistor-based ion sensors show an intrinsic trade-off between sensitivity, operating range and supply voltage. To overcome these limitations, here we focus on ion sensor amplifiers where complementary OECTs are integrated in a push-pull configuration, providing sensitivity larger than 1 V/dec at a supply voltage down to 0.5 V and operating in the physiological range. Ion detection over a range of five orders of magnitude and real-time monitoring of variations two orders of magnitude lower than the detected concentration are achieved. The ion-sensitive amplifier sets a new benchmark for ion-sensing devices, opening possibilities for predictive diagnostics and personalized medicine.