Colloids and Surfaces B: Biointerfaces 94 (2012) 114–117 Contents lists available at SciVerse ScienceDirect Colloids and Surfaces B: Biointerfaces j our na l ho me p age: www.elsevier.com/locate/colsurfb One step green synthesis of silver nano/microparticles using extracts of Trachyspermum ammi and Papaver somniferum K. Vijayaraghavan a,∗ , S.P. Kamala Nalini b , N. Udaya Prakash c , D. Madhankumar d a Centre for Nanotechnology, BIST, Bharath University, Selaiyur, Chennai 60073, Tamil Nadu, India b Department of Plant Biology & Plant Biotechnology, Sir Theagaraya College, Chennai 600021, Tamil Nadu, India c Research & Development Vel Tech Dr RR & Dr SR Technical University, Avadi, Chennai 600062, Tamil Nadu, India d Marina Labs, Chennai 600093, Tamil Nadu, India a r t i c l e i n f o Article history: Received 7 November 2011 Received in revised form 20 January 2012 Accepted 20 January 2012 Available online 30 January 2012 Keywords: Biomaterials Nanoparticles Trachyspermum ammi Papaver somniferum Silver Green synthesis a b s t r a c t A novel biosynthesis route for silver nanoparticles (Ag-NPs) was attempted in this present investigation using aqueous extracts of Trachyspermum ammi and Papaver somniferum. The main constituents in T. ammi are thymol, p-cymene and -terpinene, while P. somniferum consists of morphine and codeine. The essential oil in T. ammi was found to be a good reducing agent than the alkaloids present in P. somniferum for the formation of biocompatible Ag-NPs. The effectiveness of both the extracts was investigated by using same dosage of extract in the synthesis of silver nanoparticle. The results showed that for the same dosage of extracts the T. ammi synthesized various size triangular shaped nanoparticles measur- ing from 87 nm, to a fewer nanoparticles having a size of 998 nm diagonally. P. somniferum resulted in almost spherical shaped particle ranging in size between 3.2 and 7.6 m diagonally. Future research based on synthesis of size specific nanoparticle based on the optimization of reaction condition would be an interesting area. © 2012 Elsevier B.V. All rights reserved. 1. Introduction Nanomaterials magnetize a lot of attention due to the remark- able difference in structural and physical properties to those of atoms, molecules and bulk materials of the same element [1,2]. Nowadays, the “green” synthesis of metal nanoparticles has received increased attention due to the advances in eco- friendly technologies in material science. Legitimacy of the “green” nanoparticle synthesis is vouched based on the nature of the sol- vent, reducing and capping agent, coupled with minimal wastage in terms of energy and raw materials, reduced impact on environment and safety in nanomaterial synthesis protocol. The nanoparticles may either be synthesized intracellularly or extracellularly using bacteria, yeast, fungi, plant materials and natural polymers such as gelatin, chitosan, proteins and starch. Green synthesis pathways are cost effective and do not use toxic chemicals, high pressure, energy and temperatures [3–7]. Bio-inspired approaches were explored in the synthesis of Ag- NPs using leaf extracts such as Crossandra infundibuliformis [8], Acalypha indica [9], Rhizophora mucronata [10], Mentha piperita [11], Azadirachta indica [12], lemongrass plant extract [13], Ste- via rebaudiana [14], Chenopodium album [15], Cassia fistula [16] ∗ Corresponding author. Tel.: +91 44 22299006; fax: +91 44 22293886. E-mail address: vijaya025@yahoo.com (K. Vijayaraghavan). and banana peel extract [17]. Silver nanoparticles have unique properties that find its way in different applications viz.: (a) in assay as biological tags and biosensors in diagnostic appli- cations, (b) incorporating Ag-NPs in apparel, footwear, wound dressings, paints, cosmetics and plastics resulted in antibacte- rial properties, (c) Ag-NPs are used in conductive inks and when incorporated in composites enhanced thermal and electrical con- ductivity and (d) Ag-NPs exhibit metal-enhanced fluorescence (MEF) and surface-enhanced Raman scattering (SERS) thus leading to optical applications [18,19]. The main objective of this work is to apply the factual principles of green chemistry in the synthesis of Ag-NPs, by using stand alone reducing and capping agent such as Trachyspermum ammi (ajwain) and Papaver somniferum (opium poppy seed) with water as a sol- vent. The synthesis method presented in the article is unique on its own till date. The main constituents in T. ammi are thymol, p- cymene and -terpinene, while P. somniferum consists of morphine and codeine. This article reveals the possibility of producing highly monodispersed, stable colloidal and biocompatible Ag-NPs. 2. Materials and methods 2.1. Preparation of extract from T. ammi and P. somniferum T. ammi and P. somniferum were purchased from a local mar- ket, and were sieved to remove impurities and sun dried for 5 h 0927-7765/$ – see front matter © 2012 Elsevier B.V. All rights reserved. doi:10.1016/j.colsurfb.2012.01.026