Histidine-Capped ZnO Nanoparticles: An Efficient Synthesis, Spectral Characterization and Effective Antibacterial Activity

Abstract

In this article, an efficient synthesis of histidine-capped ZnO nanoparticles was carried out in absolute ethanol by using solvothermal technique. The synthesized nanoparticles were further characterized by using different techniques such as powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), Fourier transfer infrared (FTIR), UV-visible spectroscopy, thermal analysis (TG/DTG/DTA) and photoluminescence spectroscopy. The XRD measurement reveals that the prepared nanoparticles have hexagonal wurtzite structure. From XRD data, the average crystalline size is calculated to be 22 nm according to half width of (1 0 1) diffraction peak using Debye-Scherrer formula. Moreover, the antibacterial activities of nanoparticles sample have been performed under standard method. The antibacterial activities of histidine-capped zinc oxide nanoparticles are tested against human bacterial pathogen such as Staphylococcus aureus, Escherichia coli, Klebsiella sp., Enterococcus faecalis and Pseudomonas aeruginosa by using agar well diffusion method. Besides, antibacterial activities of ZnO nanoparticles (20 to 60 μg) are compared with four well-known antibiotics viz., Amikacin (30 mcg), Ciprofloxacin (5 mcg), Gentamicin (5 mcg) and Norfloxacin (10 mcg). From antibacterial studies, it has been concluded that if the concentration of histidine-capped ZnO nanoparticles increases, then the antibacterial activities also increase.