Bimetallic Ag/Cu incorporated into chemically exfoliated MoS₂ nanosheets to enhance its antibacterial potential: in silico molecular docking studies

Bimetallic Ag and Cu (1:1 wt%) nanoparticles (NPs) were synthesized and annealed at temperatures of 400 °C, 600 °C, and 800 °C using chemical reduction techniques. High temperature annealed (at 800 °C) Ag:Cu sample ratios (5 and 10 wt%) were used to dope MoS₂. A wide variety of techniques including X-ray diffraction, Fourier transform infrared spectroscopy, field emission scanning, high resolution transmission electron microscopy, differential scanning calorimetry, thermogravimetric analysis, Raman, photoluminescence, and ultraviolet visible spectrophotometry were used to study the morphology, structure, functional groups, excitons recombination, and thermal and optical properties of both annealed and doped samples. The antimicrobial activity of the prepared products was tested on the MRSA-superbug with ciprofloxacin antibiotic as the reference drug. Statistically significant (P < 0.05) inhibition zones (mm) were recorded for the as-synthesized Ag-Cu, heat-treated samples at 400 °C, 600 °C, and 800 °C, doped Ag–Cu/MoS₂ 5% and Ag–Cu/MoS₂ 10% which ranged from 6.35–9.85 mm and 8.60–11.75 mm at (0.5, 1.0 mg 50 μl⁻¹) concentrations compared with ciprofloxacin 12.55 mm and DIW 0 mm inhibition zones, respectively. Overall Ag–Cu NPs alone and with different temperature treatments showed less antibacterial efficacy compared with Ag–Cu/MoS₂ 5% and 10%. Furthermore, molecular docking studies were employed to unveil the binding interaction pattern of NPs in the active pocket of β-lactamase enzyme suggested that it could be a potential inhibitor that could be further evaluated for its enzyme inhibition characteristics. (paper)