Synergistic multifunctional biomedical activity of microwave-synthesized Au/Pt/Cu trimetallic nanofluids: experimental and DFT insights.

In the present study, a trimetallic Au/Pt/Cu nanofluid was synthesized via a rapid one-pot microwave-assisted strategy and systematically evaluated for multifunctional biomedical activity. Structural and spectroscopic characterization confirmed the formation of an integrated multimetallic nanostructure, likely to contain alloyed or compositionally mixed domains that generate synergistically active interfaces of Au, Pt and Cu. The nanofluid exhibited broad-spectrum antimicrobial activity, inhibiting Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis) and Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa) with a minimum inhibitory concentration (MIC) of 0.0137 µmol mL-1. Enhanced antifungal efficacy was observed against Rhizopus oryzae and Candida albicans (MIC = 0.0068 µmol mL-1), with activity against C. albicans surpassing that of fluconazole under identical conditions. The anti-inflammatory potential evaluated through bovine serum albumin denaturation revealed an IC50 of 14.88 ± 0.09 µM, while antioxidant capacity measured using the DPPH assay showed an IC50 of 4.34 ± 0.08 µM, indicating effective free-radical scavenging in the low-micromolar range. These findings highlight a synergy-driven mechanism integrating catalytic redox modulation, biomolecular interactions, and enhanced physicochemical compatibility.