Structural, Optical, and Bioactivity Properties of Silver-Doped Zinc Sulfide Nanoparticles Synthesized Using Plectranthus barbatus Leaf Extract

Aqueous leaf extract of Plectranthus barbatus was used, for the first time, for preparation of (2, 6 mol%) silver (Ag)-doped zinc sulfide nanoparticles (ZnS NPs), acting as a stabilizing and capping agent for NPs’ production. The obtained metal oxides were characterized by FTIR, UV-visible, XRD, and SEM methods. The results revealed that 0.02 and 0.06% Ag-doped ZnS had optical bandgaps of 3.20 and 3.03 eV. The XRD evinced the crystalline nature, while the FTIR confirmed the doped structure of the prepared oxides. The bioactivity investigations revealed that the biosynthesized Ag-doped ZnS NPs are more active against S. aureus than E. coli. Furthermore, the hemolytic tests indicated no potential harm to red blood cells if utilized at a low dose. Such enhanced optical and biological properties of Ag-doped ZnS may promote its prospective use in electronics and as an antibacterial agent.