TL;DR: In this particular paper, the authors noted the plant-mediated synthesis of silver nanoparticles using the plant leaf extract of Coleus aromaticus, which acts like a decreasing and capping agent. According to the distinctive properties of optical Fano resonance and plasmonic-waveguide coupling units, this paper explores a novel refractive index https://www.directivepublications.org/journal-of-applied-nanoscience/