Differential Pulse Voltametric Detection of Dopamine Using Polyaniline-Functionalized Graphene Oxide/silica Nanocomposite for Point-of-care Diagnostics.

In this study, a novel composite material, GO/SiO2@PANI, was synthesized and employed as an electrochemical sensor for the detection of dopamine in urine using differential pulse voltammetry (DPV). This work introduced a first-time combination of graphene oxide (GO) with silicon dioxide (SiO2) and the conducting polymer polyaniline (PANI) to improve dopamine detection. The composite material was synthesized using an in situ polymerization process, ensuring uniform integration of GO/SiO2 with PANI. The GO/SiO2@PANI-modified glassy carbon electrode (GCE) demonstrated a notable electrocatalytic activity for dopamine detection using DPV and CV. The performance of the sensor was evaluated across a range of dopamine concentrations, showing a linear detection range between 2 and 12 μM with a detection limit of 1.7 μM and relative standard deviation of 2.5%. The material's performance was attributed to the combined effects of graphene's surface area, PANI's conducting properties, and the structural integrity provided by SiO2 nanoparticles (NPs). Additionally, the sensor's robustness and high selectivity were confirmed through tests with synthetic urine samples, where dopamine concentrations were detected with high accuracy. This work provides a promising avenue for the development of low-cost and efficient dopamine sensors for clinical applications.