143 ISSN: 2348-1900 Plant Science Today http://www.plantsciencetoday.online Research Article Efficient synthesis of plant-mediated silver nanoparticles and their screening for antimicrobial activity Rashmi Dwivedi, 1 Bhoopander Giri, 2 and Kamlesh Shukla 3* 1 Department of Biotechnology, Guru Ghasidas Central University, Bilaspur, India 2 Department of Botany, Swami Shraddhanand College, University of Delhi, Delhi, India 3 Department of Biotechnology, Pt. Ravishankar Shukla University, Raipur, India Artic le history Received: 08 August 2017 Accepted: 01 September 2017 Published: 11 September 2017 © Dwivedi et al. (2017) Editor K K Sabu Publisher Horizon e-Publishing Group Correspondence Kamlesh Shukla kshukla26@yahoo.co.in Abstract Now days, the development of safe, cost effective, reliable and eco-friendly processes for the synthesis of nanoparticles is an important aspect of nanotechnology. Among the various agents, plants show immense potential for the synthesis of nanoparticles. The bio-molecules found in plants induce reduction of Ag + ions from silver nitrate to silver nanoparticles (AgNPs); therefore, in the present work, the aqueous leaves extract of the plant was used as reducing agent for the synthesis of silver nanoparticles. We synthesized extracellular silver nanoparticles using extract of the leaves of four different medicinal plants which act as a reducing agent at room temperature. The characteristic color change was observed on addition of plant extract to the silver nitrate solution due to their specific properties (Surface Plasmon Resonance). UV-Vis spectroscopy was used for the characterization of the silver nanoparticles. Green synthesized nanoparticles are evaluated for their antimicrobial activity against the Gram-positive and Gram-negative bacteria as well as two pathogenic fungi Aspergillus fumigatus and Curvularia lunata. The silver nanoparticles (SNPs) of selected plant parts have shown more toxicity towards bacterial species than that of the fungal species. Comparing with simple plant extracts, the SNPs exhibited greater antimicrobial efficacy and advantage over conventional antibiotics to which these microorganisms usually impart resistance. Keywords SNPs; Plant extract; Antimicrobial activity; Nanobiotechnology Citation Dwivedi R, Giri B, Shukla K. Efficient synthesis of plant-mediated silver nanoparticles and their screening for antimicrobial activity. Plant Science Today 2017;4(3):143-150. doi: 10.14719/pst.2017.4.3.328 1 Introduction Nanotechnology refers to an extensive area of research with a unifying theme of controlling matter size from micrometer to nanometer which is known as nanoparticles, which constitute the fundamental building blocks of nanotechnology. Owing to their extensive applications, several artificial methods have been developed ISSN: 2348-1900 Horizon e-Publishing Group Plant Science Today (2017) 4(3): 143-150 http://dx.doi.org/10.14719/pst.2017.4.3.328