Root system of live plants is a powerful resource for the green synthesis of Au-nanoparticles

Abstract

Sixteen plant species from 11 distinct families were evaluated for their potential to exogenously fabricate Au-nanoparticles (NPs) at the root surface. The root system of intact plants of all species turned clear pale yellow colloidal salt solutions of Au purple/golden. Transmission electron microscopy coupled with energy dispersive X-ray spectroscopy revealed the presence of Au-NPs in the range of 5-100 nm in these colloidal solutions. PXRD showed the crystalline nature of Au-NPs. Reduction of 2,6-dichlorophenol-indophenol (DCPIP) by the root system of intact plants confirmed that the root surface possesses the strong reducing strength necessary for the reduction of Au 3+ to Au 0 and to generate Au-NPs. Our findings unequivocally demonstrated for the first time that roots of intact plants of certain species can be exploited for the bulk synthesis of Au-NPs exogenously under ambient conditions in an aqueous phase. These findings highlight a novel, simple, economically feasible and green/eco-friendly scheme for the exogenous production of Au-NPs in an aqueous phase under ambient conditions.

Reducing Strength Prevailing at Root Surface of Plants Promotes Reduction of Ag+ and Generation of Ag0/Ag2O Nanoparticles Exogenously in Aqueous Phase

“…Earlier, it had been unequivocally proven that root system of plant species possess strong reducing capacity [32]–[36].…”

In Vivo Biosynthesis of Inorganic Nanomaterials Using Eukaryotes—A Review

“…The as-obtained Au NPs displayed interesting catalytic properties. However, these studies did not determine the yield nor the kinetics of the plant-mediated Au 3+ bioconversion into Au NPs [ 60 ].…”

“…Adapted from Ref. [ 60 ] permission from the Royal Society of Chemistry (RSC). ( h – k ) Localization of Ag NP within the plant tissues of Brassica juncea : ( a ) leaf, ( b ) lower section of outer stem, ( c ) root and ( d ) lower section of inner stem.…”

Biofabricación de nanopartículas de metales usando células vegetales o extractos de plantas

“…It has a series de NPs de metales, aunque también se encuentran resultados acerca de la biosíntesis de nanomateriales como el grafeno (Gurunathan et al, 2014). Se dispone de una serie de revisiones de literatura que señalan muchos casos específicos, incluyendo las especies vegetales utilizadas para la biofabricación de NPs, así como los elementos transformados a NPs (Iravani, 2011;Baker et al, 2013;Rai y Yadav, 2013;Pardha-Saradhi et al, 2014b;Ahmed and Ikram, 2015;Keat et al, 2015).…”

“…Por otra parte para la fabricación biológica de NPs es posible utilizar cultivos de bacterias o cianobacterias (Patel et al, 2015), hongos (Ahmad et al, 2003), microalgas (Patel et al, 2015) o bien cultivos de células u órganos vegetales (AlShalabi y Doran 2013), plantas completas (Mittal et al, 2014) o sus estructuras, por ejemplo brotes (Gardea-Torresdey et al 2003), flores y tallos (Kuppusamy et al, 2016) o raíces (Pardha-Saradhi et al, 2014b). El proceso de fabricación biológica puede ocurrir de forma intracelular (Haverkamp and Marshall 2008), extracelular (Li et al, 2011) o inclusive ex planta por medio de los exudados radicales (Pardha-Saradhi et al, 2014a).…”