Bactericidal Impact Of Nickel-Oxide Nanoparticles On Foodborne Pathogens: Complementary Microbiological And Ir-Spectroscopic Insights

Food pathogens (Staphylococcus aureus, Listeria monocytogenes, and Pseudomonas aeruginosa) in planktonic form were subjected to bactericidal treatment by colloidal nanoparticles. NiOx colloidal nanoparticles, as anti-biotic nanomaterial, were produced by laser ablation in deionized water and air, and comprehensively characterized by x-ray diffraction, scanning electron microscopy, energy dispersive X-ray, Raman, Fourier transformed infrared (FT-IR) spectroscopy, dynamic light scattering size and zeta-potential measurements. Normalized Fourier transformed infrared (FT-IR) spectra of the nanoparticle-inactivated bacteria deposits exhibit for the larger, positively charged water-borne nanoparticles pronounced enhancement of IR-absorption in molecular fragments, comprising the bacterial membrane, which appears to be unfavorable for the inactivation of the food bacteria strains. In contrast, smaller and less charged air-borne nanoparticles exhibit less influence in IR-absorption, but pronounced TEM-envisioned penetration inside these pathogenic bacteria, resulting, according to the complementary microbiological tests, in their efficient inactivation. The study will help to understand the possible mechanisms responsible for the death of bacteria at their interacting with antibacterial nanoparticles.