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

Abstract

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 manag- ing 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.

Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This work was supported by the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement BioInspireSensing no. 955643. Agència de Gestió d’Ajuts Universitaris i de Recerca, AGAUR (grant number: 2021 SGR 00387), by Generalitat de Catalunya (Spain). MCIN/AEI/https://doi.org/10.13039/501100011033 (grant number: Maria de Maeztu Units of Excellence Programme CEX2023-001300-M).

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Postprint (published version)