Assessment of antimycobacterial activity and DFT studies of green-mediated CdO-doped Ag nanoparticles using Diethyl phthalate enriched <i>Sauropus androgynus</i> leaf extract

Tuberculosis (TB) is a potentially fatal disease. The need for novel anti-tubercular drugs has arisen due to the emergence of a high degree of treatment resistance and the predominance of Mycobacteria other than TB (MOTT). Accordingly, the current study reports the facile production of silver and silver-cadmium oxide nanomaterials utilizing leaf extract from Sauropus androgynus. The synthesized nanoparticles (NPs) were characterized using an ultraviolet-visible spectrophotometer (UV-Vis), X-Ray Diffraction analysis (XRD), Scanning Electron Microscope (SEM), Energy Dispersive X-Ray analysis (EDAX), High Resolution Transmission Electron Microscope analysis (HR-TEM), and fourier transform infrared (FTIR) studies. An aggregated spherical form with Ag, Cd, and O signals was observed in the SEM-EDAX analysis, and the XRD shows distinctive crystallinity. For the Ag-CdO nanocomposite and bare AgNPs, the average particle size was 17 nm and 23 nm, respectively, as determined by HR-TEM analysis. Ag and Ag-CdO NPs demonstrated distinct inhibition zones ranging from 13 to 16 mm, demonstrating their inhibitory efficacy, when the antibacterial activity was tested against Staphylococcus and Pseudomonas at various concentrations. A promising in vitro antimycobacterial activity against M. smegmatis was also demonstrated by the Ag-CdO nanocomposite. According to Density Functional Theory (DFT) studies, diethyl phthalate (DP) found in Sauropus androgynus leaf extract is what causes the extract to function as a reducing agent when Ag+ ions are reduced to Ag0. Good ligand interaction was shown in molecular docking studies of PDB ID: 5D6N, which correlated with the in vitro antimycobacterial activity. As a result, the synthesized NPs may be useful as antibacterial and antitubercular agents.