Hindawi Publishing Corporation International Journal of Carbohydrate Chemistry Volume 2013, Article ID 539636, 10 pages http://dx.doi.org/10.1155/2013/539636 Research Article A Green Approach to Synthesize Silver Nanoparticles in Starch-co-Poly(acrylamide) Hydrogels by Tridax procumbens Leaf Extract and Their Antibacterial Activity Siraj Shaik, 1 Madhusudana Rao Kummara, 2 Sudhakar Poluru, 1 Chandrababu Allu, 1 Jaffer Mohiddin Gooty, 3 Chowdoji Rao Kashayi, 4 and Marata Chinna Subbarao Subha 1 1 Department of Chemistry, Sri Krishnadevaraya University, Anantapur, Andhra Pradesh 515 003, India 2 Department of Polymer Science and Engineering, Pusan National University, Busan 609-735, Republic of Korea 3 Department of Microbiology, Sri Krishnadevaraya University, Anantapur, Andhra Pradesh 515 003, India 4 Department of Polymer Science & Tech, Sri Krishnadevaraya University, Anantapur, Andhra Pradesh 515 003, India Correspondence should be addressed to Marata Chinna Subbarao Subha; mcssubha3@gmail.com Received 31 August 2013; Accepted 13 November 2013 Academic Editor: Roland J. Pieters Copyright © 2013 Siraj Shaik et al. Tis 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. A series of starch-co-poly(acrylamide) (starch-co-PAAm) hydrogels were synthesized by employing free radical redox poly- merization. A novel green approach, Tridax procumbens (TD) leaf extract, was used for reduction of silver ions (Ag + ) into silver nanoparticles in the starch-co-PAAm hydrogel network. Te formation of silver nanoparticles was confrmed by UV- visible spectroscopy (UV-Vis), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray difraction (X-RD) studies. 22% of weight loss diference between hydrogel and silver nanocomposite hydrogel (SNCH) clearly indicates the formation of silver nanoparticles by TGA. TEM images indicate the successful incorporation of silver nanoparticles ranging from 5 to 10nm in size and spherical in shape with a narrow size distribution. Tese developed SNCHs were used to study the antibacterial activity by inhibition zone method against gram-positive and gram-negative bacteria such as Bacillus and Escherichia coli. Te results indicated that these SNCHs can be used potentially for biomedical applications. 1. Introduction Hydrogels have three-dimensional polymeric networks that are fabricated from polymers stabilized through physical or chemical crosslinking. Tey absorb large quantities of water without losing their structural integrity [1]. Since they mimic body tissues and respond to external stimuli, they are made important and promising forms of biomaterials for various applications including tissue engineering, controlled drug release devices, biosensors, and mechanical actuators [2– 4]. Due to the presence of water solubilizing groups, such as –OH, –COOH, –CONH 2 , –CONH–, and –SO 3 H, these hydrogels show higher hydrophilicity. Te three-dimensional network of hydrogel provides relative stability to its structure. Teir swollen state results from a balance between the dispersing forces acting on hydrated chains and cohesive forces that do not prevent the penetration of water through the network [5]. Based on these properties the hydrogels have been used recently as templates for production of metallic nanoparticles. Hence the design and development of metal nanoparticles dispersed in polymer matrix have attracted potential applications in various felds like electrical, optical, or mechanical properties [6, 7] making them valuable for applications in areas like optics [8], photo imaging and patterning [9], electronic devices [10], sensors and biosensors [11–13], catalysis [14, 15], and antibacterial and antimicrobial coatings [16]. Silver nanoparticles (Ag NPs) have attracted considerable interest in biological studies because of their ease of preparation, good biocompatibility, and relatively large surface area [17, 18]. Ag NPs have many important appli- cations in biomedical felds, sensors, and flters [19]. Addi- tionally, silver is a potential antibacterial agent [20] and is