Unveiling the PEDOT-polypyrrole hybrid electrode for the electrochemical sensing of dopamine

This study presents the electrochemical sensing of dopamine (DA) using an electrode of polypyrrole/poly(3,4-ethylenedioxythiophene) (PEDOT-PPy) thin film. Electrochemical analyses of the PEDOT-PPy thin film for DA sensing were conducted through cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The CV analysis demonstrated that PEDOT-PPy exhibited superior electrochemical activity towards DA due to its enhanced conductivity as a high-conducting polymer composite. The DPV results indicated a linear concentration level of 5 nM to 200 µM with a minimal limit of sensing of 5 nM using the PEDOT-PPy electrode material. The fabricated sensor explored the sensitivity of 7.27 µA/µM cm² at the 5 to 1000 nM DA concentration and the dopamine diffusion coefficient of 1.3 × 10^–8 cm²/s. Additionally, the PEDOT-PPy electrode material displayed excellent reproducibility, selectivity, and stability. Therefore, the PEDOT-PPy composite electrode material shows excellent potential for outperforming other electrode materials in detecting DA.