The aim of the present study was to evaluate the in vitro antimicrobial activity of pet-ether, dichloromethane and methanol fractions of Swertia chirata (Family: Gentianaceae) ethanolic extract. Disc diffusion technique and food poison method were used for antibacterial and antifungal activity, respectively. Dichloromethane fraction from both leaf and stem showed significant antimicrobial activities against some Gram-positive and Gram-negative bacteria and mild to moderate activity against some fungi. A large zone of inhibition was observed (19 mm) against Staphylococcus aureus. Test materials at a concentration of 400 microg disc(-1) were used to evaluate the antimicrobial activity while Kanamycin at a concentration of 30 microg disc(-1) was used as positive control in this study. Among different fractions, dichloromethane fraction showed significant antimicrobial activity against Gram-positive, Gram-negative and fungi. The most significant antimicrobial activity was seen against Staphylococcus aureus which reflects it potentiality to be used in skin infections.
Zinc oxide (ZnO) thin films were coated onto Indium Tin Oxide (ITO) glass substrate using spin coating technique as a function of annealing temperature. The thin film preparation was undertaken by utilising zinc acetate dihydrate, ethanol and diethanolamine as the precursors. The films were coated at room temperature prior to being annealed at temperatures ranging from 300 °C to 450 °C. The resulting crystalline structure and surface morphology of the thin films were then examined using X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). UV-visible spectrophotometer was also used to record the optical absorbance in wavelengths ranging from 200 to 800 nm. The findings revealed that the ZnO thin films showed a single phase of wurtzite with n-type semiconductor, with the lowest value of band gap energy of 3.28 eV for ZnO thin films annealed at 350 °C. FESEM results showed that the ZnO nanoparticles were very compact on the surface, whereby the average particle size was equivalent to 108.5, 115.3, 108.2 and 107.8 nm at the temperatures 300 °C, 350 °C, 400 °C, and 450 °C, respectively. Additionally, the highest photoconversion efficiency (0.11%) recorded for the sample was annealed at 350◦C. Thus, annealing temperature was found to significantly affect the optical and electrical properties of ZnO nanoparticle seed layer, as well as its band gap energy and surface morphology.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.