Impact of surfactant (EDTA) on the properties of zinc sulphide nanoparticles and their antibacterial activity

Abstract

In the present study solvothermal route is chosen to synthesize uncapped and EDTA capped zinc sulphide (ZnS) nanoparticles. X-ray diffraction studies confirmed the zinc-blende crystal structure with crystallite size lying between 6 and 16 nm. Scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM) show the prominent decrease in agglomeration of capped nanoparticles than that of uncapped nanoparticles while the elemental analysis confirmed the presence of Zinc and Sulphur. The optical band gap increased with decrease in particle size as calculated by UV-visible absorption spectroscopy. The photoluminescence spectroscopy (PL) shows that the blue-visible emission peaks are shifted to higher wavelength region for uncapped nanoparticles than that of EDTA capped nanoparticles. The presence of different organic and inorganic functional groups and encapsulation of EDTA in the prepared samples are confirmed by Fourier Transform Infrared Spectroscopy (FTIR). The synthesized nanoparticles are found to be good antibacterial agents of Escherichia coli and Staphylococcus aureus. The objective of the present work is to show that the EDTA capped nanoparticles are found more resistant towards the bacterial strains than that of uncapped nanoparticles which is the novelty of our work and the activity increases with increase in the concentration of nanoparticles. Thus, they may be used for biological and medicinal purposes such as an antiseptic, photo corrosion, antioxidant, antifungal etc.