Antibacterial and nonlinear dynamical analysis of flower and hexagon-shaped ZnO microstructures

Rajat K Saha,Eeshankur Saikia,Mrinal K Debanath,Bishaldip Paul,Subhash Medhi

doi:10.1038/s41598-020-59534-x

Abstract

The present study reports the antibacterial properties of flower-shaped ZnO (FZnO) microstructures and its comparison with that of hexagon-shaped bulk ZnO (BZnO) nanostructures. The samples are prepared successfully by wet chemical method and the surface morphologies, structures and size of the ZnO samples are characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), BET adsorption isotherm, and Photoluminescence (PL) Spectroscopy. The SEM and TEM images of the sample have confirmed flower-shaped structure of the ZnO. The materials are also analyzed by using an innovative tool called Lacunarity, a nonlinear dynamical (NLD) tool for proper understanding of the inherent surface properties of the particles formed, comparing the results estimated with the BET results obtained, thereby confirming our proposition to use it as an important parameter in predictive models. In this new approach, geometry of the surface structure is being associated with biological properties, in order to come up with easier ways to identify materials for any such applications where rich surface structure is desired. The photocatalytic activity of the flower-shaped material is carried out to find out its optical properties as another marker for confirming the antimicrobial activities. It has been reported for the first time that the prominent antibacterial activities are favoured by the FZnO microstructure having lesser Lacunarity, significantly better than its bulk counterpart, for inhibiting gram negative - Escherichia coli microorganism.

Highlights

Nanotechnology, at present, pertains to creation of useful materials, devices, and systems through appropriate manipulation of matter
The as-prepared samples are characterized by X-ray diffraction (XRD)[6], Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) to find their size and shape[7,8]
The other sample bulk ZnO (BZnO) is introduced for comparative study of the nonlinearity, to predict the strong possibility of flower-shaped ZnO (FZnO) in inhibiting microorganisms[5]

Summary

Introduction

Nanotechnology, at present, pertains to creation of useful materials, devices, and systems through appropriate manipulation of matter. Two important attributes, capping and molarity, are used to control the particle size and their agglomeration[3] It is reported in W Yu et al (2016), that photo-generated electrons in ZnO are much lighter than their corresponding holes, which indicates that it belongs to the n-type semiconductor[4]. Flower-shaped ZnO (FZnO) microstructures in PVP matrix and uncapped hexagon-shaped bulk ZnO (BZnO) nanostructures are synthesized for the study of their antimicrobial properties. It was reported that the optical property of FZnO microstructure and its antimicrobial activity were regulated by surface-volume ratio of the granules[11]. More ZnO NPs aggregate spontaneously along active sites for the growth of flower-shaped ZnO microstructure due to their high surface-to-volume ratio and high surface energy. Capping agent PVP tends to adsorb on the {10–10} planes of the six symmetric side facets of the growth nuclei, thereby it allows to occur only along the polar axis[14,20,21]

Methods

Results

Conclusion