Bio-templated Synthesis of Multi-functional Bimetallic Ag–Cu Nanospheres: Unveiling Therapeutic Potential

Abstract

Antimicrobial medicines serve as the bedrock of modern medical practices. Increasing multidrug resistance compromises surgical processes and increases healthcare costs. Therefore, a combinational approach has become a pre-requisite for sustainable medical care. In recent decade, biologically synthesized metallic nanoparticles have emerged as a class of potent antimicrobials. In this study, green synthesized bimetallic silver–copper oxide (Ag–Cu) nanospheres have been prepared using the culture supernatant of the Bacillus subtilis (MTCC 441) bacteria to effectively target infectious microbes. The hydrodynamic diameter of the nanoparticles as depicted by dynamic light scattering (DLS) was 143.5 nm, while the polydispersity index (PI) of 0.367 and zeta potential of −25.2 mV indicated toward uniform size distribution and excellent colloidal stability. The Ag–Cu nanospheres of diameter 22.24 ± 8.01 nm were prepared using the culture supernatant of B. subtilis MTCC 441. High-end techniques such as transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy revealed the size (22.24 ± 8.01 nm), spherical morphology, crystal structure and surface functionalization of nanospheres, respectively. The antimicrobial potential of the nanospheres was assessed against multidrug-resistant (MDR) bacterial strains while anti-free radical capacity was evaluated through 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and H2O2 free radical inhibition. The anti-inflammatory study was also performed to investigate the biomedical potential of the synthesized Ag–Cu nanosphere. The comprehensive analysis of antimicrobial, anti-oxidative and anti-inflammatory assays presents Ag–Cu nanospheres spheres as suitable candidates to be used in various biomedical applications.