Plant-Mediated Synthesis and Characterization of Silver and Copper Oxide Nanoparticles: Antibacterial and Heavy Metal Removal Activity

The advancement in conservationist strategies for development of nanoparticles is elemental to the subject of nanotechnology. Green protocols are highly preferred over conventional methods as they are environmentally benign. Certain phytochemicals in plant extracts exhibit natural tendencies of bio-reduction of salts. They also possess the ability of stabilizing these reduced particles by capping them. In present study leaf extract of Catharanthus roseus, an evergreen subshrub has been utilized for production of AgNPs and CuO-NPs. Synthesized nanoparticles were evaluated for their cadmium, chromium removal and antibacterial potential against S. aureus. AgNPs and CuO-NPs were optimized by varying salt concentration, leaf extract concentration and time interval to obtain better yield. UV-Vis spectroscopy was used to detect biogenic AgNPs and CuO-NPs. Wavelength range used for AgNPs and CuO-NPs was 300-700 and 200-700 nm successively. The morphology of nanoparticles was determined to be spherical and within 100 nm using SEM images. FT-IR investigation confirmed the presence of amines and alcohols in AgNPs. IR spectra of CuO-NPs revealed the ubiety of aldehydes/ ketones and carboxylic acids. The average distribution for silver was 602.9 nm and for copper was1066 nm as confirmed by DLS analysis. Further zeta-potential for AgNPs and CuO-NPs was recorded -16.4 mV and -6.18 mV. Kirby Bauer test for S.aureus show maximum ZOI i.e. 16 mm in case of AgNP (50 mu l) and 10 mm in case of CuO-NP (50 mu l). Highest chromium and cadmium removal was observed in case of biogenic silver nanoparticles i.e. 47.84% and 5.68% respectively. This is the first work that presents a comparative study of biogenic AgNPs and CuO-NPs from the leaf extract of Catharanthus roseus. Our findings can also help in improving the current scenario of metalloid pollution in soil and water environments. Hence, proper scaling up can make biogenic AgNPs and CuO-NPs a noteworthy tool in industries as well.