Abstract Full-Text PDF Full-Text HTML Full-Text ePUB Linked References How to Cite this Article Bioinorganic Chemistry and Applications Volume 2014 (2014), Article ID 784268, 8 pages http://dx.doi.org/10.1155/2014/784268 Research Article Sonochemical Synthesis of Silver Nanoparticles Using Starch: A Comparison Brajesh Kumar, 1 Kumari Smita, 1 Luis Cumbal, 1 Alexis Debut, 1 and Ravinandan Nath Pathak 2 1 Centro de Nanociencia y Nanotecnologia, Universidad de las Fuerzas Armadas (ESPE), Sangolqui, Ecuador 2 Department of Chemistry, Kolhan University, Chaibasa, Jharkhand 833202, India Received 21 October 2013; Revised 25 November 2013; Accepted 26 November 2013; Published 22 January 2014 Academic Editor: Konstantinos Tsipis Copyright © 2014 Brajesh Kumar et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract A novel approach was applied to synthesize silver nanoparticles using starch under sonication. Colloidal silver nanoparticles solution exhibited an increase of absorption from 420 to 440 nm with increase starch quantity. Transmission electron microscopy followed by selected area electron diffraction pattern analysis indicated the formation of spherical, polydispersed, amorphous, silver nanoparticles of diameter ranging from 23 to 97 nm with mean particle size of 45.6 nm. Selected area electron diffraction (SAED) confirmed partial crystalline and amorphous nature of silver nanoparticles. Silver nanoparticles synthesized in this manner can be used for synthesis of 2-aryl substituted benzimidazoles which have numerous biomedical applications. The optimized reaction conditions include 10 ml of 1 mM AgNO 3 , 25 mg starch, 11 pH range, and sonication for 20 min at room temperature. 1. Introduction Nanoscale materials have received considerable attention because their unusual optical, chemical, photoelectrochemical, and electronic properties differ significantly from those of atoms and molecules as well as those of bulk materials [1–3]. The synthesis of nanomaterials with the desired quality is one of the most exciting aspects in modern nanoscience and nanotechnology [4]. Colloidal nanoparticles are small in diameter but large in surface area and huge in current many exclusive medical and industrial applications such as biological engineering, catalysts, and electronic devices [5]. Colloidal silver nanoparticle (Ag-NP) with natural macromolecule can be fabricated by physical [6, 7] and chemical reduction [8–10] methods. Nowadays, biomass starch as a raw material for the synthesis of Ag-Nps has reflected significant superiority in some process. However, no literature is available on its preparation in starch at different pH and polysaccharide by ultrasonic field. The sonochemical methods are as follows: formation, development, and the implosion of the microcavities [11]. When solutions are exposed to ultrasonic irradiation, bubbles in the solution could be imploded by acoustic fields. Cavitation’s bubble collapse can also induce a shock wave in the solution and drive the rapid impact of the liquid to the surface of the particles [12]. Use of the sonoelectrochemical method for the preparation of spheres, rods, and dendrites shaped Ag-Nps with nitriloacetate (NTA) [13]. It was found that the electrolyte composition that comes along reaction time can greatly affect the shape and growth of the NPs. Branched silver structure with 440 nm and average diameter of 11.5 nm was formed using an aqueous extract of Mesua ferrea Linn. leaf [14]. Nagata and coworkers formed stable colloidal dispersions of silver prepared by ultrasonic irradiation of aqueous AgNO 3 or AgClO 4 solutions in the presence of surfactants [15]. Amorphous Ag-NPs of 20 nm size were prepared from an aqueous solution of AgNO 3 using argon-hydrogen atmosphere [16] and AgBr in the presence of gelatin [17]. Sonochemical route using a hazardous reducing agent (NaBH 4 ) produced spherical silver nanoparticles of sizes 10 nm [18]. Many methods aiming at the formation of Ag-Nps, including the green ones, make use of an organic molecule. The latter interacts with the particles and provides them with stability against oxidation and agglomeration, or it can even act as a matrix only. In this sense, polymer molecules have been widely employed because their long chain offers many binding sites in which nanoparticles can be stabilized [19]. Moreover, natural polymers are extremely important because many of them are biocompatible and nontoxic. Among such biomolecules are sucrose [20], maltose [20], chitosan [21], Arabic gum [22], and plant extracts such as the ones obtained from Jatropha curcas [23], Murraya koenigii, [24] and Mangifera indica [25]. More specifically, the natural rubber latex (NRL) extracted from Hevea brasiliensis, a native tree from the Amazon forest, arises as a possible biomaterial for use in the synthesis of nanoparticles [26]. The use of green capping and stabilizing attribute of starch in aqueous solution has recently become important in synthesis methods of nanomaterials, due to the fact that this biopolymer acts as an effective surfactant agent and is environmentally friendly. It is possible to Hindawi Publishing Corporation Impact Factor 1.165 Bioinorganic Chemistry and Applications