Colossal antibacterial, antibiofilm and solar light-driven photocatalytic activity of nanoenhanced conjugate of bimetallic Ag-Zr nanoparticles with graphene oxide

The study focuses on structural, optical, morphological, photocatalytic, antibacterial, and antibiofilm activities of bimetallic Ag-Zr nanoparticles (NPs) decorated on graphene oxide nanosheets. The bimetallic Ag-Zr NPs were prepared using biological synthesis and were characterized by various characterization techniques such as X-ray diffraction (XRD), Fourier transform infra-red (FTIR), Raman spectroscopy, high-resolution transmission electron microscopy (HR-TEM), scanning electron microscopy (SEM) along with EDX, UV-Vis, and photoluminescence (PL) spectroscopy for their structural, morphological, and optical analysis. The photocatalytic activity was measured using the degradation of a well-known methylene blue (MB) organic dye under sunlight irradiation, while the antibacterial activity was tested against human pathogenic bacteria viz. Methicillin-resistant Staphylococcus aureus (MRSA). The results revealed that the Ag-Zr NPs exhibited significantly enhanced photocatalytic and antibacterial activity with low MICs as compared to individual Ag or Zr nanoparticles. Furthermore, the nanoparticles significantly inhibited biofilm formation, with up to a 71% reduction in biofilm formation at a highest sub-MIC. The enhanced activities were attributed to the synergistic effect of the bimetallic nanoparticles and the graphene oxide support at very low concentration. This study suggests that the bimetallic Ag-Zr nanoparticles decorated on graphene oxide (Ag-Zr/GO) could be a promising material for various applications such as wastewater treatment, antibacterial and antibiofilm agents.