Silver doped copper oxide decorated graphene oxide nanocomposite for electrochemical sensing, photocatalysis and biomedical applications

Abstract

A silver-doped copper oxide nanocomposite decorated on graphene oxide (Ag–CuO@GO) was synthesized via a facile wet-chemical method and characterized using XRD, SEM, FTIR, UV-vis, and EDX analyses. The synergistic combination of Ag and CuO onto GO provided greater charge separation, better conductivity, and a high surface-area framework for uniform nanostructure distribution. Electrochemical studies confirmed excellent sensing performance toward dopamine, with rapid electron transfer kinetics and a low limit of detection (23.6 μM) and higher sensitivity of 3.43 mA cm⁻² mM⁻¹. Correspondingly, photocatalytic studies revealed that Ag–CuO@GO showed remarkable dye degradation capability. Ag–CuO@GO achieved up to 96% degradation of MB under direct sunlight with 0.3 mg mL⁻¹ catalyst loading in 30 minutes. While kinetic studies at 0.2 mg mL⁻¹ followed pseudo-first-order kinetics with an apparent rate constant of 0.019 min⁻¹. Additionally, due to the intrinsic biomedical properties of Ag and CuO, the nanocomposite also exhibits notable antibacterial activity, further broadening its potential practical utility. These results confirm Ag–CuO@GO as an efficient multi-functional material for electrochemical sensing, photocatalytic degradation of organic dyes and antibacterial activity.