Centella asiatica mediated facile green synthesis of nano zinc oxide and its photo-catalytic and biological properties

Abstract

The aim of this research is to employ Gotukola (Centella Asiatica) to prepare multifunctional ZnO nanocrystals through solution combustion synthesis. PXRD pattern reveals the obtained particles belongs to hexagonal wurtzite system . Debye sherrercalculations reveal that the particle sizes were 7, 8 and 11 nm. TEM and SEM images shows that the particles have porous and sponge-like morphology. A sharp peak at 443 nm in PL spectra was observed due to Zn and O-vacancies. FTIR spectra exibits the broad peak caentered at 3441 cm−1 corresponds to the O-H stretching frequencies. Further the catalyst shows excellent photocatalytic activity towards the degradation of environmental pollutants like methylene blue and methyl orange and eosin yellow, and also acts as good free radical scavenger. It effectively inhibits the free radical activity of 1,1-Dipheny-2- picrylhydrazyl (DPPH). It also exhibit the antibacterial activity against the E.coli, P.desmolyticum, P.eruginosa, K.aerogenes, and Aureus pathogenic bacterial strains. ZnO-Nps were tested for their antidiabetic ability, and they showed excellent - glucosidase (IC50 of 95.55 μg/ml) and - amylase (IC50 of 84.00 μg/ml) inhibitory activities. The cytotoxic effects of ZnO Nps on the HeLa cell line were investigated using the MTT test, which revealed a dose-dependent action. The IC50 value was found to be 232 μg/ml, indicating that they have a greater cytotoxic potency. The synthesised nanoparticles also acts as a strong anticoagulant agent. The study demonstrates preparation of multifunctional ZnO Nps using a Solution Combustion Synthesis method that is quick, economical and eco sustainable.