Abstract:
Recently, green technology through biosynthesis method has drawn great attention compared to
the physical and chemical methods. NPs produced by plant extracts are more stable and
biocompatible in comparison with those produced by other methods. Physical and chemical
method used, hence green synthesis is inexpensive, low cost and environmentally friendly. This
research focused on the synthesis of MnO NPs and Ag-MnO NCs using C. macrostachyus leaf
extracts and evaluation of their antimicrobial activities. The synthesized nanoparticles were
characterized by using UV-Vis, FT-IR, XRD, SEM, and CV. From UV-Vis absorption spectrum
the peaks of MnO NPs and Ag-MnO NCs were detected at 230 and 232 nm. The FT-IR
spectroscopy revealed the presence of secondary metabolites like phenols, flavonoids, alkaloids,
and others in the synthesized nanoparticles and nanocomposites. The crystalline structure were
examined the XRD technique, the results indicated that the synthesized NPs had amorphous nature
and Ag-doped has 25.54 nm crystalline size. The SEM images of MnO NPs and Ag-MnO NCs
indicate formation of pentagon shaped MnO NPs the morphology polymorphic and slightly the
agglomerate size which changed to rod-like shape on doping. The reduction of metal ion during
stabilization by phytochemicals while forming MnO NPs and Ag-MnO NCs were characterized
by CV. The antimicrobial activity of the plant extract and the synthesized NPs was determined by
measuring the zone of inhibition. The synthesized Ag-MnO NCS exhibits activity against two
gram positive (S. aureus and B.cereus) and two gram negative (E. coli and S. typhi) bacterial as
well as fungal (candida albicans) test. Therefore, the current study reveals a convenient utilization
of Croton macrostachyus extract as a reducing agent for the successful synthesis of Ag-MnO NCs
through a green synthesis method to obtain significantly active antimicrobial material.
