Phytochemical Reduction of Heavy Metal Ion Cd <sup>2+</sup> to Stable CdO Using Ethanolic Extract of <i>Limonia acidissima</i> Leaves and Antimicrobial Investigation Thereof

Abstract

Secondary metabolites from plants are used for various applications including pharmaceutical, dye degradation and metal reduction. The major reasons for the application of secondary metabolites in these fields are the low cost, surplus resource and biocompatibility. In this research, we have used the phenolic compounds of Limonia acidissima for the reduction of heavy metal cadmium from its salt state (CdSO4) into its metallic oxide state and tested its anti-microbial potency. The secondary metabolites of Limonia acidissima themselves possess anti-microbial activity against gram negative bacteria. The phenolic compounds are also capable of reducing the metallic salts into metal oxides with the transfer of electrons and functionalize the surface of the particles. Thus the ethanolic extract of L.acidissima was used to synthesize CdO nanoparticles by colloidal precipitation method. The synthesized nanoparticles were characterized using XRD for crystal lattice arrangement and FE-SEM for the size and shape of the nanoparticles. The antimicrobial activity of the nanoparticles was compared with the antimicrobial potency of the plant extract and was found to be increased on the introduction of nanoparticles. This work thus provides the anti-bacterial and heavy metal reduction wealth from the effluent and agrowaste.