Biological synthesis of silver nanoparticles; its characterization and therapeutic potential using Grewia optiva leaves extract

Abstract The standard technologies and hazardous chemicals used in the synthesis of silver nanoparticles (Ag-NPs) can be harmful to the environment and as well as for human health. Sustainable and eco- friendly method of synthesizing nanoparticles are required. To synthesize silver nanoparticles (Ag-NPs), Grewia optiva leaf extract was used in the current research as a reducing agent. The leaves were thoroughly cleaned and dried before forming in an aqueous solution using a Jeldal apparatus for 20 minutes at 100 ºC. For the purpose, the extract and the silver nitrate (AgNO3) solution were thoroughly mixed. The method of synthesizing nanoparticles was optimized through the manipulation of multiple parameters, such as pH, temperature, and salt content. It was found that the ideal temperature for the synthesis of nanoparticles was 85 °C, the ideal pH range was 6-7, and the ideal salt concentration was 2 mL. Different techniques were used for characterization, including X-ray diffraction (XRD) to determine the crystalline structure of nanoparticles, Fourier-transform infrared spectroscopy (FT-IR) to identify chemical bonds and functional groups, using an Energy Dispersive X-ray Spectrometer (EDX) and transmission electron microscopy (TEM) to determine particle size in detail, and scanning electron microscopy (SEM) to analyze morphological aspects. The biosynthesized Ag-NPs showed potent antibacterial, phytotoxic, insecticidal, antipyretic, and analgesic properties in addition to efficient radical scavenging. The results showed that Ag-NPs made from G. optiva aqueous extract are appropriate for the production of novel medical and agricultural remedies. Since this study was carried out in a lab, more investigation is required to determine whether large-scale production is feasible and to look into possible uses of these Ag-NPs in the agricultural and biomedical sectors.