Biogenic synthesis of ZnO nanoparticles mediated from Borassus flabellifer (Linn): antioxidant, antimicrobial activity against clinical pathogens, and photocatalytic degradation activity with molecular modeling.

Dharman Kalaimurugan,Palaniappan Sivasankar,Muthugoundar Subramanian Shivakumar,Wen-Chao Liu,Kandhasamy Lalitha,Balasubramanian Balamuralikrishnan,Srinivasan Venkatesan,Sungkwon Park,Kaliannan Durairaj,Kannan Nithya

doi:10.1007/s11356-021-18074-1

Abstract

Borassus flabellifer leaf extract has been used for rapid biogenic synthesis of zinc oxide nanoparticles (ZnO-NPs) due to rich source of bioactive compounds. The synthesized ZnO-NPs were preliminarily confirmed by UV-visible spectroscopy adsorption peak range at 365nm. The XRD (X-ray diffraction) confirms purity of ZnO-NPs that were crystalline in nature. The analysis of FT-IR (Fourier-transform infrared spectroscopy) confirms the presence of the following functional group such as alcohol, phenols, carboxylic acids, primary amides, secondary amides, and alkyl halide. TheField Emission Scanning Electron Microscope (FE-SEM) analysis indicated that ZnO-NPs were in spherical shape, followed by EDX analysis which confirmed the presence of Zn-element. Antimicrobial effect of ZnO-NPs was investigated using different clinical pathogens like bacteria Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Klebsiella Pneumonia, and Pseudomonas aeruginosa and fungi Aspergillus flavus, Candida albicans, and Penicillium expansum which confirmed ZnO-NPs efficiency as an antimicrobial agent. ZnO-NP antimicrobial efficiency was observed in higher zone of inhibition at 50μg/mL concentrations. Antioxidant activity was ascertained to be used for several biomedical applications. The ZnO-NPs efficiently degraded the environmental toxic dyes (methylene blue and crystal violet) under sunlight, and up to 95% higher degradation was achieved in both dyes. In support of photo light degradation, the study was progressed to understand the ZnO-dye interaction stability using molecular mechanism, and it shows efficient bonding features in the NPs environment. Overall, this investigation has great potential for being an effective and eco-friendly material used in environmental applications.

Highlights

Nanotechnology is one of the most fascinating ideas which is to develop particles with nano size for the use in various fields of science and technology such as increased surface area, catalytic efficiency, profuse reactive sites as well as high absorption rates (Dhand et al 2015; Cittrarasu et al 2019)
In this study, using B. flabellifer leaf extract (BFLE) as reduction agent we aimed at green synthesis of Zinc-Oxide nanoparticles (ZnO-NPs) and characterized by UV-visible spectroscopy, Xray diffractometer (XRD), Field Emission Scanning Electron Microscope (FE-SEM), Energy-dispersive X-ray spectroscopy (EDS)
BFLE with ZnSO4 solution showed colour change to dark brown, that confirms the presence of Zinc oxide (ZnO)-NPs

Summary

Introduction

Nanotechnology is one of the most fascinating ideas which is to develop particles with nano size for the use in various fields of science and technology such as increased surface area, catalytic efficiency, profuse reactive sites as well as high absorption rates (Dhand et al 2015; Cittrarasu et al 2019). Recent studies have shown that inc oxide nanoparticles (ZnO-NPs) have potent toxicity to bacteria but exhibit minimal effects on human cells (Reddy et al 2007). In this study, using BFLE as reduction agent we aimed at green synthesis of ZnO-NPs and characterized by UV-visible spectroscopy, Xray diffractometer (XRD), Field Emission Scanning Electron Microscope (FE-SEM), Energy-dispersive X-ray spectroscopy (EDS). Further investigated their antibacterial, antifungal activity against representatives of clinical pathogenic microorganisms, antioxidant activity of radical scavenging activity and photocatalytic degradation of methylene blue and crystal violet dyes under sunlight along with in-silico molecular docking analysis to shed more light on the pharmaceutical and industrialized research findings

Methods

Results

Conclusion