Green Synthesis of Silver Nanoparticles Using Polyalthia longifolia Leaf Extract along with D-Sorbitol: Study of Antibacterial Activity

摘要

Synthesis of silver nanoparticles (AgNPs) using Polyalthia longifolia leaf extract as reducing and capping agent along with D-sorbitol used to increase the stability of the nanoparticles has been reported. The reaction is carried out at two different concentrations (10~(-3) M and 10~(-4) M) of silver nitrate, and the effect of temperature on the synthesis of AgNPs is investigated by stirring at room temperature (25~ °C) and at 60°C. The UV-visible spectra of NPs showed a blue shift with increasing temperature at both concentrations. FT-IR analysis shows that the biomoites played an important role in the reduction of Ag~+ ions and the growth of AgNPs. TEM results were utilized for the determination of the size and morphology of nanoparticles. The synthesized silver nanoparticles are found to be highly toxic against Gram-positive bacteria than Gram-negative bacteria.