BACKGROUND: Silver nanoparticles (AgNPs) are widely used in food industries, biomedical, dentistry, catalysis, diagnostic biological probes, and sensors. The use of plant extract for AgNPs synthesis eliminates the process of maintaining cell culture and the process could be scaled up under a non-aseptic environment. The purpose of this study is to determine the classes of phytochemicals, to biosynthesise and characterise the AgNPs using Clinacanthus nutans leaf and stem extracts. In this study, AgNPs was synthesised from the aqueous extracts of C. nutans leaves and stems through a non-toxic, cost effective and eco-friendly method.

RESULTS: The formation of AgNPs was confirmed by UV-Vis spectroscopy, and the size of AgNP-L (leaf) and AgNP-S (stem) were 114 and 129 nm, respectively. Transmission electron microscopy (TEM) analysis showed spherical nanoparticles with AgNP-L and AgNP-S ranging from 10-300 nm and 10-180 nm; with zeta potentials of AgNP-L and AgNP-S at -42.8 and -43.9 mV, respectively. XRD analysis matched the face-centred cubic structure of silver and was capped with bioactive compounds. FTIR analysis revealed the presence of few functional groups of phenolic and flavonoid compounds. These functional groups act as reducing agents in AgNPs synthesis.

CONCLUSION: This result showed that the biogenically synthesised nanoparticles reduced silver ions to silver nanoparticles in aqueous condition and the AgNPs formed were stable and less toxic.