Carbon quantum dots composite for enhanced selective detection of dopamine with organic electrochemical transistors

A compact organic electrochemical transistors (OECT) sensor enriched with carbon quantum dots (CQDs) was developed to enhance the transconductance of an electropolymerized poly(3,4-ethylenedioxythiophene) (PEDOT) film, enabling the precise and selective detection of dopamine (DA). Accurate monitoring of DA levels is critical for diagnosing and managing related conditions. Incorporating CQDs, we have achieved a remarkable up to threefold increase in current at the DA detection peak in differential pulse voltammetry. This enhancement showcases superior selectivity even in the presence of high concentrations of interferents like uric acid and ascorbic acid. This material significantly boosts the sensitivity of OECTs for DA detection, delivering an amperometric response with a detection limit of 55 nM and a broader detection range (1 - 500 µM). Our results underscore the potential of low-dimensional carbonaceous materials in creating cost-effective, high-sensitivity devices for detecting DA and other biomolecules. This breakthrough sets the stage for the development of next-generation biosensors for point-of-care diagnostics.