Phytosynthesis of Nickel Oxide Nanoparticles and Their Antioxidant and Antibacterial Efficacy Studies.

Abstract

Multidrug-resistant (MDR) bacteria are widely acknowledged as a significant and pressing public health concern. Tribulus terrestris has been used as a health tonic in traditional medicine since ancient Vedic times. It was also utilized to synthesize small, well-dispersed metal nanoparticles (NPs). Thebiosynthesized nickel oxidenanoparticles (NiO-NPs) have a broad spectrum of biomedical uses. The objective of the research was to utilize a green synthesis method to synthesizeNiO-NPsusing Tribulus terrestris, subsequently characterize, and this study aimed to assess the antioxidant and antibacterial effectiveness of these NPs against wound isolates that are resistant to multiple drugs. The synthesis of NiO-NPs was achieved through the titration method, which is a green synthesis approach, and it was characterized by using techniques such as ultraviolet-visible spectroscopy (UV), Fourier transform infrared (FT-IR), scanning electron microscopy (SEM),X-ray diffraction (XRD) analysis, andenergy dispersive X-ray (EDX). The antioxidant activity of theNPs was evaluated using the 2,2-diphenyl-1-picrylhydrazyl(DPPH) assay, and antibacterial activity was done using the agar well diffusion method. IBM SPSS Statistics for Windows, Version 21 (Released 2012; IBM Corp., Armonk, New York, United States)is used for statistical analysis. The biosynthesized NiO-NPs exhibited acolor change from dark brown to dark green, indicating the successful reduction of the NPs.UV analysis peaks were observed at 310-350 nm, whileFT-IRanalysis showed the peaks at various wavelengths such as 629.31cm-1(halo compound; C-Br stretching), 957.80cm-1(aromatic phosphates; P-O-C stretch), 1004.65cm-1 (aliphatic phosphates; P-O-C stretch), 1094.93cm-1(organic siloxane or silicone; Si-O-Si), 1328.38cm-1(dialkyl/aryl sulfones), 1604.88cm-1(open-chainazo-N=N-), 2928.68cm-1 (methylene C-H asym/sym stretch), 3268.65cm-1(normal polymeric "OH" stretch). The crystallinity of the NPs was determined to be 24.7%, while the remaining 75.6% exhibited an amorphous structure. The SEM image revealed a spherically agglomeratedstructure of the nano-ranged size NiO-NPs.TheEDX analysis indicated the presence of elemental compositions Ni (7.4%), O (39.4%), and C (53.3%)in the biosynthesized NiO-NPs. These NPs demonstrated significant antibacterial activity against Pseudomonas aeruginosa and Klebsiella pneumoniae, moderate antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA), and the lowest antibacterial activity against Enterococcus faecalis. Our in vitro results demonstrate that the biosynthesized NiO-NPsexhibit significant antioxidant and antibacterial activity. These NPs can be used as a future antimicrobial medication, particularly against MDR clinical wound isolates ofK. pneumoniae, P. aeruginosa, and MRSA.