Formation of ZnO Micro-Flowers Prepared via Solution Process and their Antibacterial Activity

Abstract

This paper presents the fabrication and characterization of zinc oxide micro-flowers and their antibacterial activity. The micro-flowers of zinc oxide composed of hexagonal nanorods have been prepared via solution process using precursor zinc acetate di-hydrate and sodium hydroxide in 3 h of refluxing time at ~90°C. The antibacterial activities of grown micro-flowers were investigated against four pathogenic bacteria namely S. aureus, E. coli, S. typhimurium and K. pneumoniae by taking five different concentrations (5–45 μg/ml) of ZnO micro-flowers (ZnO-MFs). Our investigation reveals that at lowest concentration of ZnO-MFs solution inhibiting the growth of microbial strain which was found to be 5 μg/ml for all the tested pathogens. Additionally, on the basis of morphological and chemical observations, a chemical reaction mechanism of ZnO-MFs composed of hexagonal nanorods was also proposed.

Flower-shaped ZnO nanoparticles synthesized by a novel approach at near-room temperatures with antibacterial and antifungal properties

“…Similar microbicidal impacts of some other ZNPs synthesized from different approaches are also known. 53,54 In most of these cases, it has been proposed that these particles interact with thiol groups of vital enzymes and subsequently inactivates them. Even though this might occur, we could not pinpoint the exact site where these ZNPs could affect the microbial cells, but it was very clear that Gram-positive bacterial strains were most susceptible to these ZNPs, which might be due to the presence of special type of cell wall structure that contains different components of charged molecules, such as surface proteins and polysaccharides.…”

From zinc oxide nanoparticles to microflowers: A study of growth kinetics and biocidal activity

“…Reports indicate that ZnO nanoparticles attach the outer wall of the cell and then enter the inner wall, leading to disruption of the cell membrane and as a result lead to disorganization and leakage [46]. Internalization of the ZNO-NSS has been observed in certain cases, but is not a general occurrence [47].…”

Synthesis, characterization and thermal decomposition kinetics of poly(2-imidazolidinthione-formaldehyde)

“…The strains were inoculated with 5 mL of freshly prepared nutrient broth medium with 50 µL strain in a 15 mL capacity cultured glass tube. The tubes were incubated in a rotary shaker at 140 rpm at 37 °C for 12 h. After the incubation the desired amount (50, 100, 150 and 200 µg/mL) poly-IF was incorporated to the bacterial suspension in the same range in all tubes [13,14]. The bacterial growth was monitored at every 3 h of regular intervals for 15 h. The changes of absorbance were measured at 600 nm via a spectrophotometer (Shimadzu, UV-2550).…”