Effect of glutathione capping on the antibacterial activity of tin doped ZnO nanoparticles

Abstract

In the present study, we first synthesized pristine ZnO and Sn doped ZnO nanoparticles (NPs) then capped the synthesized NPs by Glutathione at different capping concentrations. The structural, morphological, and optical properties of synthesized NPs was examined by x-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive x-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), UV–visible, and energy resolved photoluminescence spectroscopy. The XRD analysis confirmed the formation of wurtzite crystal structure of ZnO nano-crystallites while TEM micrographs showed the formation of dendrite nanostructure at higher capping concentration of glutathione in Sn doped ZnO NPS. Strong absorption band around 2525 cm−1 in the IR spectrum indicates the presence of S–H stretching vibration of glutathione which has been disappeared in glutathione capped ZnO NPs. Blue shift in absorption edge was observed in glutathione capped ZnO NPs as compared to uncapped NPs. Moreover, the synthesized NPs showed excellent response against both Gram positive bacteria (Streptococcus sp. & Staphylococcus sp.) and Gram negative (E. coli & Klebsiella sp.) bacteria. Maximum zone of inhibition has been observed with glutathione capped Sn doped ZnO nanostructures. Hence, it can be concluded from the present investigation that the optimization of capping concentration will be very beneficial to exploit Sn doped ZnO semiconductor nanostructures as a coating material for different chemotherapeutic drugs.