Preferential killing of bacterial cells by surface-modified organosilane-treated ZnO quantum dots synthesized through a co-precipitation method

Abstract

The aim of this study was to screen and determine the significant antibacterial/antiviral activities of zinc oxide quantum dots owing to their impressive activities against microorganisms. This study was focused on enhancing the antibacterial activity of ZnO QDs by MPS organosilane surface modification. The precipitation method was used to synthesize ZnO QDs and ZnO@MPS. Ultraviolet reflectance spectroscopy (UV-DRS) and solid-state photoluminescence spectroscopy were used to confirm the surface modification of ZnO QDs and MPS. The outcome of other characterization studies showed that ZnO QDs have exhibited better dispersion, size reduction and lower aggregation than pure ZnO QDs. This paved the path to reveal that MPS modification was effective on the surface of ZnO QDs. The antibacterial activities of the synthesized materials were determined using the agar disc diffusion method with the help of Gram-negative and Gram-positive bacterial strains such as Escherichia coli, Staphylococcus aureus, Enterococcus faecalis and Klebsiella pneumoniae. The surface modified ZnO@MPS QDs showed remarkable zones of inhibition against the tested Gram-positive bacteria rather than the Gram-negative bacteria due to their reduced particle size. Hence it is suggested that the synthesized surface modified ZnO@MPS QDs can be used as better promising antibacterial agents.