Ag-Conjugated Nanoparticle Biosynthesis Mediated by Rosemary Leaf Extracts Corre-lates with Plant Antioxidant Activity and Pro-tein Content

In recent years, the world has witnessed an explosion of interest in biogenic synthesis of metallic na-noparticles (NPs), using plant extracts; however, the plant constituents involved in this reaction are poorly characterized. Here, major components of Rosemary (Rosmarinus officinalis L.) leaf extracts were isolated monthly during 2012-2013 and their competences for Ag–conjugated nanoparticle biosyn-thesis were studied. Formation of Ag/AgCl–NPs was examined using UV-visible spectroscopy and char-acterized by Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), and Transmission electron microscopy (TEM). Correlation analysis showed that extracts with more protein contents and higher total reducing capacity were more efficient in biosynthesis of Ag/AgCl–NPs. There existed no correlation between total phenolic, ascorbic acid and anthocyanin contents with Ag/AgCl–NPs biosynthesis activity. These results partly explain the mechanisms controlling plant mediated bio-synthesis of nanoparticles, with possible applications in standardization of plant materials harvested throughout a year.