Optimizing gold electrode surface treatments for enhanced dopamine detection: A comparative study

This study investigates the effects of various surface modification techniques on the performance of gold electrodes for the electrochemical detection of dopamine, which may serve as a foundation for further development of biosensors. Three distinct treatments—sulfuric acid treatment, plasma treatment, and self-assembled monolayers—were systematically evaluated to optimize the electrochemical properties of the electrodes. Following surface treatments, gold nanoparticles and laccase were used to modify the gold electrode to investigate the biosensor's analytical capabilities and compare the influence of different treatment techniques. Key performance parameters, including sensitivity, selectivity, limit of detection, and linearity, were rigorously assessed. The results revealed that sulfuric acid-treated electrodes exhibited superior performance, achieving lower detection limits and improved reproducibility compared to other treatments (linear range: 0.1 – 200 µM, with limit of detection equal to 13.4 nM, sensitivity 3.7 μA·mM −1 cm −2 , high selectivity and great accuracy). This research underscores the importance of electrode surface modifications in developing effective biosensors for real-time monitoring of neurotransmitters, with implications for clinical diagnostics and neurological research. • Investigation of sulfuric acid, plasma, and SAMs for optimizing gold electrodes in dopamine biosensing. • Integration of AuNPs and laccase significantly improves electrochemical response and stability. • Assessment of key metrics such as sensitivity, selectivity, and limit of detection across different surface modifications. • Sulfuric acid-treated electrodes demonstrate the best performance in detection limits and reproducibility. • Findings highlight the potential for optimized surface treatments to enhance real-time neurotransmitter monitoring.