Green synthesis of bio-molecule encapsulated magnetic silver nanoparticles and their antibacterial activity.

Persuaded by the necessity of finding new sources of antibiotics, silver nanoparticles (Ag NPs) were synthesized by adopting a newly developed green synthesis technique and subsequently, their antibacterial activity against different pathogenic bacteria was evaluated. We have successfully synthesized bio-molecule capped ferromagnetic Ag NPs with an average crystallite size of 13 nm using AgNO 3 solution as a precursor and Artocarpus heterophyllus leaf extract as a reducing and capping agent. The characterization of the synthesized Ag NPs was carried out using various techniques such as UV-visible (UV-Vis) spectroscopy, energy dispersive X-ray (EDX) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), thermogravimetry (TG), and vibrating sample magnetometer (VSM) analyses. After exposing the synthesized Ag NPs to two Gram-positive bacteria - Staphylococcus aureus and Bacillus cereus and two Gram-negative bacteria - Escherichia coli and Salmonella typhimurium , the zones of inhibition were found to be 15, 16, 19, and 18 mm, respectively. These results imply that the Artocarpus heterophyllus leaf extract mediated green synthesized bio-molecules encapsulated Ag NPs can be considered as a potential antibiotic against human pathogens which is very encouraging.