NiS2 nanoparticles: structural, spectroscopic and significant antibacterial properties against series of pathogenic strains.

Antibacterial properties of nanoparticles are very useful in diverse application including water disinfection, medicines, textile industries and food packaging. The present work addresses the first-time investigation on the antibacterial properties of NiS₂ nanoparticles against five Gram-positive and five Gram-negative bacterial strains, using the well diffusion method, in terms of zone of inhibition (ZOI) and minimum inhibitory concentration (MIC). NiS₂ nanoparticles were synthesized by hydrothermal method using Teflon-lined stainless-steel autoclave, and characterized using X-ray diffraction (XRD), UV-visible spectroscopy (UV-Vis), energy-dispersive X-ray spectroscopy (EDX) and Scanning electron microscopy (SEM) techniques. SEM analysis shows that the size of synthesized nanoparticle was 30-50 nm. NiS₂ nanoparticles shows significant antibacterial activity against both the Gram-positive and Gram-negative bacterial strains. Notable increase in the antibacterial activity is observed for NiS₂ nanoparticles with the increase in its concentration in terms of ZOI, which helps us to study the cell toxicity. MIC of NiS₂ is also predicted for representative Gram-positive and Gram-negative bacterial strains. The results of the present work are expected to contribute significantly toward possible medicinal applications of NiS₂ nanoparticles.