Colloids and Surfaces A: Physicochem. Eng. Aspects 339 (2009) 134–139 Contents lists available at ScienceDirect Colloids and Surfaces A: Physicochemical and Engineering Aspects journal homepage: www.elsevier.com/locate/colsurfa Green synthesis of silver nanoparticles using latex of Jatropha curcas Harekrishna Bar, Dipak Kr. Bhui, Gobinda P. Sahoo, Priyanka Sarkar, Sankar P. De, Ajay Misra ∗ Department of Chemistry and Chemical Technology, Vidyasagar University, Midnapore 721 102, West Bengal, India article info Article history: Received 16 September 2008 Received in revised form 5 February 2009 Accepted 6 February 2009 Available online 20 February 2009 Keywords: Green synthesis Silver nanoparticles Jatropha curcas SPR abstract Silver nanoparticles were successfully synthesized from AgNO 3 through a simple green route using the latex of Jatropha curcas as reducing as well as capping agent. Nanoparticles were characterized with the help of HRTEM, X-ray diffraction and UV–vis absorption spectroscopy. X-ray diffraction analysis showed that the nanoparticles were of face centered cubic structure. A comparison of radius of nanoparticles obtained from HRTEM image with the optimized cavity radius of the cyclic peptides present within the latex revealed that the particles having radius 10–20nm are mostly stabilized by the cyclic peptides. © 2009 Elsevier B.V. All rights reserved. 1. Introduction Metal nanoparticles are intensely studied due to their unique optical, electrical and catalytic properties. To utilize and optimize chemical or physical properties of nano-sized metal particles, a large spectrum of research have been focused to control the size and shape, which is crucial in tuning their physical, chemical and optical properties [1–3]. Various techniques, including chemical and phys- ical means have been developed to prepare metal nanoparticles, such as chemical reduction [4–7], electrochemical reduction [8,9], photochemical reduction [10,11], heat evaporation [12,13] and so on. In most cases, the surface passivator reagents are needed to pre- vent nanoparticles from aggregation. Unfortunately many organic passivators such as thiophenol [14], thiourea [15], marcapto acetate [16], etc. are toxic enough to pollute the environment if large scale nanoparticles are produced. Biosynthesis of nanoparticles has received considerable atten- tion due to the growing need to develop environmentally benign technologies in material synthesis. For instance, a great deal of effort has been put into the biosynthesis of inorganic materials, especially metal nanoparticles using microorganisms [17–22]. Both live and dead microorganisms are gaining importance by virtue of their facile assembly of nanoparticles. Moreover, the problems con- cerning the synthesis of nanoparticles and their stabilization can be solved in tandem and mild conditions. Among microorganisms, prokaryotic bacteria have primarily attracted the most attention [17]. An important demonstration was reported by Klaus et al. [23] who describe the formation of silver-based particles at the cell poles ∗ Corresponding author. Tel.: +91 9433220206; fax: +91 3222275329. E-mail address: ajaymsr@yahoo.co.in (A. Misra). of propagating Pseudomonas stutzeri AG259. Sastry and co-workers [24,25] have opened the field to the synthesis of metal nanoparti- cles by eukaryotic organisms like Verticillium sp. They demonstrated that the shift from bacteria to fungi had the added advantage that processing and handling of the biomass would be much sim- pler. Some well-known examples of bio-organisms synthesizing inorganic materials include magnetotactic bacteria (which syn- thesize magnetic nanoparticles) [26–28], S-layer bacteria [29,30], etc. While microorganisms such as bacteria, actinomycetes and fungi continue to be investigated in metal nanoparticles synthesis, the use of parts of whole plants in similar nanoparticles synthesis methodologies is an exciting possibility that is relatively unex- plored and under exploited. Even though gold nanoparticles are considered bio-compatible, chemical synthesis methods may still lead to the presence of some toxic chemical species absorbed on the surface that may have adverse effects in medical applica- tions. Synthesis of nanoparticles using microorganisms or plants can potentially eliminate this problem by making the nanoparti- cles more bio-compatible. Use of plant extract for the synthesis of nanoparticles could be advantageous over other environmen- tally benign biological processes by eliminating the elaborate process of maintaining cell cultures. Jose-Yacaman and co-workers [31,32] first reported the formation gold and silver nanoparticles by living plants. The above synthetic protocol by plant extract or biomass exemplifies the promising application of the green synthe- sis of metal nanoparticles. Very recently green silver nanoparticles have been synthesized using various natural products like green tea (Camellia sinensis) [33], neem (Azadirachta indica) leaf broth [34], natural rubber [35], starch [36], aloe vera plant extract [37], lemongrass leaves extract [38,39] leguminous shrub (Sesbania drummondii) [40], etc. 0927-7757/$ – see front matter © 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.colsurfa.2009.02.008