Synthesis, characterization of zirconia doped cobalt nanoparticles (Zr doped Co-NPs) and investigation of their antibacterial activity

The present study was conducted to synthesise aerogel and xerogel solids based on zirconia doped with cobalt using solgel procedure. The obtained nanoparticles (Zr doped Co-NPs) were further characterized with high resolution scanning electron microscopy, energy-dispersive X-ray spectroscopy and Diffuse reflectance spectroscopy. Additionally, the antimicrobial activity of Zr doped Co-NPs was assessed against Gram-positive and Gram-negative pathogenic bacteria. Our results revealed that synthesized Co/Zr aerogels have a regular spherically shaped, heavily aggregated as groups of clusters with nanometric sizes. Regarding the antibacterial properties, synthetized nanoparticles were found to more effective against Escherichia coli and Klebsiella pneumoniae with of inhibition zones reaching 15 mm at a concentration of 35 mu g/mL. The same result was registered against Staphylococcus aureus strain at a higher concentration (45 mu g/mL). However, no activity was observed against Enterococcus faecalisstrain. The varied structure and morphologies of the tested nanomaterials influenced their antibacterial capabilities, since aerogel particles are dotted of spherical form and nanometric size. Whereas xerogels particles are nearly irregular in shape and larger in size.