Current Research in Green and Sustainable Chemistry (Jun 2020)
Design of experiment based methodical optimization and green syntheses of hybrid patchouli oil coated silver nanoparticles for enhanced antibacterial activity
Abstract
The current monologue reports the facile synthesis of hybrid Patchouli oil (P. cablin) coated silver nanoparticles (P-Ag-NPs) using hyacinth bean (L. purpureus) seed extract as a reducing agent. Design of experiment (DoE) based methodical optimization of the formulation parameters such as metallic salt concentration, and pH resulted in the successful accomplishment of the desired attributes i.e. morphology, and particle size. State of art spectroscopic (UV–Vis, DLS, ATR-FTIR, EDS), and microscopic techniques (HR-TEM, FE-SEM mapping) based characterization of the attained nanoparticles was carried out.The outcome of the respective UV–Vis analysis ascertained the biogenic synthesis, as the absorption maxima of the obtained particles (~415 nm) lied within characteristic SPR region of the Ag-NPs. DLS analysis revealed that the fabricated nanoparticles were nanosized (110 nm), and possessed a significantly high surface charge (−20.73 mV). ATR-FTIR spectra illustrated the presence of varied functional groups which confirmed the imperious role played by the phytoconstituents in reducing and capping of the synthesized P-Ag-NPs. Electron microscopic analysis further strengthened these findings, as no signs of intermittent agglomeration were present, and the P-Ag-NPs were uniformly distributed.HR-TEM also illustrated that the synthesized hybrid metallic nanoparticles were spherical, and encompassed a coating of essential oil on the halo of the as-synthesized NPs. FE-SEM-Mapping confirmed the phase purity of the Ag-NPs and showed that the particles primarily comprised of the elemental silver in nano form. DPPH and antibacterial assay revealed a significantly high antioxidant (i.e. 2.76 fold) and antibacterial (i.e. 3 fold) potential of the P-Ag-NPs as compared to its counterparts, respectively. The present work thus paves a gallant and promising pathway to eradicate the unsurmountable predicament of microbial pathogenesis.
