Synthesis of functionalized Cu:ZnS nanosystems and its antibacterial potential

Abstract

Copper doped Zinc Sulfide (Cu:ZnS) nanoparticles were synthesized as potential antibacterial agents, through a solvothermal approach using Mercaptosuccinic acid (MSA) and Sodium citrate (SC) as differential capping agents. Multiple variants of the Cu:ZnS nanoparticles were generated based on the refluxing intervals of the reactions and a choice of the capping agents. The microstructural properties and the elemental composition of the synthesized nanosystems were examined using Scanning Electron Microscopy (SEM) and powder X-ray Diffraction (XRD), along with Energy-Dispersive X-ray spectroscopy (EDX) and Microwave Plasma-Atomic Emission Spectroscopy (MP-AES). The as-synthesized nanosystems were also characterized for their surface attributes using Fourier Transform Infrared spectroscopy (FT-IR), while the optical properties were studied using UV–Vis spectroscopy. The electrostatic stability of the aqueous dispersions of Cu:ZnS was studied as a function of their solvent pH, using Photon Correlation Spectroscopy. For the assessment of the antibacterial properties of the different variants of Cu:ZnS nanosystems, the disk diffusion assay was performed against both Gram-positive and Gram-negative bacteria. The results show a promising antibacterial activity for the Cu:ZnS variants synthesized, with a prominent activity in the MSA@Cu:ZnS nanoparticle making them a novel class of potential antibacterial agents.