The need of non-toxic synthesis protocols for nanoparticles arises developing interest in biogenic approaches. The present project was focused on cost effective, environment congenial synthesis of Ag nanoparticles and their biological applications. Leaf and root extracts of Ricinus communis were used as a reducing and stabilizing agent in synthesis process. A Proposed mechanism in published literature suggested that Indole-3-acetic acid, l-valine, triethyl citrate, and quercetin-3-0-p-d-glucopyranoside phytoconstituents of Ricinus communis act as reducing and capping agents. The synthesized Ag NPs were characterized with a help X-ray diffractometer, Transmission electron microscopy, UV-Vis spectrophotometry and Fourier Transform Infrared Spectroscopy (FTIR). The XRD results inveterate the synthesis of pure nano size crystalline silver particles. The FTIR data revealed the possible functional groups of biomolecules involved in bio reduction and capping for efficient stabilization of silver nanoparticles. TEM analysis confirmed the almost spherical morphology of synthesized particles with mean size 29 and 38 nm for R-Ag-NPs (root) and L-Ag-NPs (leaf), respectively. The stability of synthesized nanoparticles was examined against heat and pH. It was observed that synthesized nanoparticles were stable up to 100 °C temperature and also showed stability in neutral, basic and slightly acidic medium (pH 05-06) for several months while below pH 5 were unstable. The synthesized silver nanoparticles had promising inhibition efficiency in multiple applications, including as bactericidal/fungicidal agents and Urease/Xanthine oxidase enzymes inhibitors. The cytotoxicity of synthesized nanoparticles shows that the concentration under 20 μg/mL were biologically compatible.
Keywords: Ricinus communis; antimicrobial activity; inhibition; silver nanoparticles; urease; xanthine oxidase.