Green Synthesis of CuO Nanoparticles using Phyllanthus Amarus Leaf Extract and their Antibacterial Activity Against Multidrug Resistance Bacteria Green synthesis of CuO nanoparticles N. P. S. Acharyulu, R. S. Dubey, V. Swaminadham Department of Nanotechnology, Swarnandhra College of Engineering and Technology, Narsapur – 534 280, India. Pratap Kollu b DST- INSPIRE Faculty, Department of Metallurgical Engineering & Materials Science, Indian Institute of Technology Bombay, Mumbai, India R. L. Kalyani Srinivasa Rao College of Pharmacy, P. M. Palem, Visakhapatnam, A.P-530041, India. S. V. N. Pammi * Advanced Analytical Laboratory, DST-PURSE Programme, Andhra University, Visakhapatnam 530003, India. Abstract— In the present study, we report biologically oriented process for green synthesis of CuO nanoparticles by using eco friendly and non-toxic Phyllanthus amarus leaf extract. Powder X-Ray Diffraction (XRD) analysis revealed that synthesized CuO nanoparticles are in monoclinic phase with average particle size of 20 nm. The antibacterial activity of these nanoparticles was tested against various multidrug resistance bacteria viz. both Gram-positive (B. subtilis and S. aureus) and Gram-negative (E.coli and P. aeruginosa). Further, these nanoparticles show higher antibacterial activity against B. subtilis followed by S. aureus, P. aeruginosa and E.coli. Keywords— nanoparticles, plant extract, multidrug resistance bacteria, Phyllanthus amarus I. INTRODUCTION Cupric oxide (CuO) nanoparticles are of significant technological interest and have attracted more attention due to its unique properties. This transition metal oxide with a narrow band gap (E g = 1.2 eV) forms the basis of several high temperature superconductors 1-4 , gas sensors 5-7 , giant magneto resistance materials 8-9 , solar energy transformation and preparation of organic–inorganic nanostructure composites 10 . Applications include as an antimicrobial, anti-fouling, anti- biotic and anti-fungal agent when incorporated in coatings, plastics and textiles 11 . Copper and copper-based compounds, due to their potent biocidal properties 12 , are now routinely used in pesticidal formulations 13 and several health related areas applications are being explored and/or implemented. Therefore, on the basis of the fundamental and practical importance of CuO nanomaterials, well-defined CuO nanostructures with various morphologies have been fabricated. There are several routes through which CuO nanoparticles can be formed, like Sonochemical 14 , microwave irradiations 15 , alkoxide based route 16 , sol–gel 17 technique, one step solid-state reaction method at room temperature 18 , electrochemical methods 19 , precipitation-pyrolysis 20 , thermal decomposition of precursor 21 or by combination of electro deposition and self-catalytic mechanism etc. Chemical synthesis methods lead to presence of some toxic chemical absorbed on the surface that may have adverse effect in the medical application. Synthesis of high-quality nanomaterials with respect to chemical purity, phase selectivity, crystallinity, and homogeneity in particle size with controlled state of agglomeration in a cost-effective procedure is still a challenge to material chemists. Moreover chemical synthesis methods lead to presence of some toxic chemical absorbed on the surface that may have adverse effect in the medical application. Increasing awareness towards green chemistry and other biological processes has led to a desire to develop an eco-friendly approach for the synthesis of nanoparticles. The use of environmentally benign materials like plant leaf extract 22 , bacteria 23 , fungi 24 and enzymes 25 for the synthesis of silver nanoparticles offers numerous benefits of eco- friendliness and compatibility for pharmaceutical and other biomedical applications as they do not use toxic chemicals for the synthesis protocol. There are various reports on metal nano particles and very few reports on metal oxide nano particles using plant extracts and other biological methods 26 . However, studies on the synthesis of CuO nanoparticles by biological method are sparse. In this study we report the green synthesis of CuO nanoparticles using Phyllanthus amarus leaf extract and study their antibacterial activity against various bacterial pathogens viz. both Gram-positive (B. subtilis and S. aureus) and Gram- negative (E.coli and P. aeruginosa). 639 Vol. 3 Issue 4, April - 2014 International Journal of Engineering Research & Technology (IJERT) ISSN: 2278-0181 www.ijert.org IJERTV3IS040918 International Journal of Engineering Research & Technology (IJERT)