Microwave-Assisted Rapid Extracellular Biosynthesis of Silver Nanoparticles Using Carom Seed (Trachyspermum copticum) Extract and in Vitro Studies

Abstract

Microwave-assisted rapid extracellular biosynthesis of silver nanoparticles was carried out by using carom seed (Trachyspermum copticum) extract as the reducing agent. The reaction mixture containing AgNO 3 and carom seed extract when exposed to microwave irradiation resulted in reducing silver ions to bio-functionalized silver nanoparticles of size 6-50 nm. The AgNP were characterized by UV-vis spectroscopy (UV-vis), X-ray diffraction (XRD), energy dispersive X-ray analysis (EDAX), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and atomic force microscopy (AFM). Themogravimetric analysis (TGA) and fourier transform infrared spectroscopy (FTIR) are used to understand the possible mechanism of biosynthesis. In this study, we have also investigated the antimicrobial and antioxidant activities of bio-functionalized AgNP. The antibacterial activity is investigated by measuring the zone of inhibition and antioxidant study is done using 1,1-diphenyl-2-picryl hydrazyl (DPPH) method.

Plant extract synthesized silver nanoparticles: An ongoing source of novel biocompatible materials

“…Silver nanoparticles prepared using Trachyspermum copticum seed has scavenged the DPPH free radical five times more effectively than butylated hydroxy anisole (BHA) at the maximum concentration of 10 g/mL. The percentage of DPPH quenching effect was found to be increased with increasing concentration of silver nanoparticles from 2.5 to 10 g/mL (Raghunandan et al, 2011b). Interestingly, Mittal et al (2012) have reported that phenolic compounds capped silver nanoparticles (synthesized from the flower extract of Rhododendron dauricum) were found to be potent free radical scavenger than the standard, Trolox.…”

“…Moreover, they have also capped around the synthesized nanoparticles, thus providing stability as well as biocompatibility. Recent studies have shown that the phytochemicals such as proteins ( Prabakar et al, 2013;Prakash et al, 2013;Santhoshkumar et al, 2011), flavonoids (Elavazhagan and Arunachalam, 2011;Philip, 2011;Raghunandan et al, 2011a;Subba Rao et al, 2013), polyphenols (Antony et al, 2011;Jeyaraj et al, 2013a;Kumar et al, 2010;Mohan Kumar et al, 2012;Njagi et al, 2011;Raghunandan et al, 2011b;Rodríguez-León et al, 2013;Roni et al, 2013;Sahu et al, 2013;Suganya et al, 2013), alkaloids (Vijayaraghavan et al, 2012), saponins (Geethalakshmi and Sarada, 2012), phenols (Lukman et al, 2011;Sathishkumar et al, 2012), essential oils (Vijayaraghavan et al, 2012), and polyols Veerasamy et al, 2011) present in the plant extracts were reported to play a major role in the bioreduction of silver ions and capping of the synthesized nanoparticles (Table 1).…”

“…Moreover, these phytosynthesized silver nanoparticles have also been shown to be effective against fungal and yeast pathogens (Singh et al, 2013). Dipankar and Murugan (2012) and Raghunandan et al (2011b) have reported the antioxidant activity of plant extract derived silver nanoparticles. Recently, the research on antitumor activity of plant extract synthesized silver nanoparticles has been emerging as one of the major thrust areas of nanobiotechnology and some studies have been directed toward validating the cancericidal property (Jacob et al, 2012;Jeyaraj et al, 2013a,b;Sankar et al, 2013;Subramanian and Suja, 2012;Vivek et al, 2012).…”

“…Besides, the biological synthesis of gold, iron, palladium, lead, copper, and other inorganic nanoparticles using plant extracts has also been reported. As evidenced from Table 1, almost all of the reported phytosynthesis methods have used water as solvent for silver nanoparticles production; nevertheless, a few studies have utilized other solvents such as acetone (Bankar et al, 2010), ethyl acetate (Kasthuri et al, 2009a), petroleum ether (Kasthuri et al, 2009b), ethanol (Raghunandan et al, 2011b;Rodríguez-León et al, 2013;Roy et al, 2010), and methanol (Arulkumar and Sabesan, 2010;Dubey et al, 2009;Kasthuri et al, 2009a,b;Shameli et al, 2012a;Zargar et al, 2011). The plant mediated synthesis method is uncomplicated since it involves in the mixing of plant extract with an aqueous solution of the related metal salt.…”

“…The plant extract synthesized silver nanoparticles have also been investigated for their antioxidant activity (Dipankar and Murugan, 2012;Mittal et al, 2012;Raghunandan et al, 2011b;Subramanian and Suja, 2012). Silver nanoparticles prepared using Trachyspermum copticum seed has scavenged the DPPH free radical five times more effectively than butylated hydroxy anisole (BHA) at the maximum concentration of 10 g/mL.…”