Synthesis of AuCu Bimetallic Nanoparticles via Electrodeposition for DPPH Free Radical Scavenging and HaCaT Cell Assays

Abstract

Bimetallic nanoparticles (NPs) have attracted significant interest in biomedical applications due to their unique physicochemical properties and synergistic effects. This study reports the synthesis of bimetallic gold-copper nanoparticles (AuCu NPs) via electrochemical deposition using cyclic voltammetry (CV) on indium tin oxide (ITO) substrates. Various precursor ratios of HAuCl₄ and CuSO₄ were employed to investigate the influence of Cu concentration on morphology and antioxidant activity of AuCu NPs. Characterization using field emission electron microscope equipped with energy dispersive X-ray spectrometer revealed that increasing Cu content altered the particle size distribution and surface uniformity, with optimal homogeneity achieved at a 1:1 Au:Cu ratio, yielding NPs of ~25–27 nm. X-ray diffraction analysis confirmed the presence of crystalline Au and Cu₂O phases, indicating successful co-deposition and surface oxidation of Cu. The antioxidant activity test, assessed through a DPPH radical scavenging assay, showed the highest inhibition (89.09%) for pure Au after a 48-hour incubation, whereas AuCu samples exhibited delayed yet substantial activity (>80%), suggesting time-dependent synergism. Furthermore, MTT assays on HaCaT cells revealed that the AuCu NPs were non-cytotoxic and exhibited protective effects against oxidative stress induced by blue light exposure, highlighting their potential for biomedical and dermatological applications.