Out of all metals, silver has been widely recognized for its antimicrobial activity over centuries of years. In more recent times, silver was found to be even more effective in antimicrobial activity when it was at nanoscale. A novel... more
Out of all metals, silver has been widely recognized for its antimicrobial activity over centuries of years. In more recent times, silver was found to be even more effective in antimicrobial activity when it was at nanoscale. A novel protocol was developed for green synthesis of silver nanoparticles and their anti-bacterial activity was experimentally validated. This protocol is different from the prior art in a way that the green synthesis from non-polar organic plant extracts is now possible for the first time. The raw material was the dichloromethane extract of Plectranthus zeylanicus, a widely used medicinal plant in Sri Lanka. Scanning electron microscopy (SEM) images of the formulation revealed that the synthesized objects were predominantly of spherical shape and approximately 100 nm in size. Energy dispersive X-ray (EDX) spectrum confirmed the presence of elemental silver in it. The presence of phytochemical classes that could be responsible for the green synthesis of nano silver was detected by standard qualitative phytochemical screening assays. The antibacterial activity of the compound was assessed by the agar well diffusion method against Gram positive and Gram negative bacteria including the methicillin resistant Staphylococcus aureus (MRSA). These new formulations exhibited profound antibacterial activity against all the tested microorganisms in comparison to aqueous silver ion solution and commercial disinfectants that contain silver ions as active ingredients. This is the first time the anti-MRSA potential of silver nanoparticles synthesized via a green route is documented. Present findings point towards the possible application of biogenic silver nanoparticles as an effective antimicrobial agent against nosocomial infections.
