Silver nanoparticle biosynthesis by using phenolic acids in rice husk extract as reducing agents and dispersants

Publication date: April 2018Source: Journal of Food and Drug Analysis, Volume 26, Issue 2Author(s): Yee-Shing Liu, Yung-Chung Chang, Hui-Huang ChenAbstractRice husk extract, obtained using acid and alkali pretreatment extraction (AAPE), contains bioactive compounds and exhibits reducing abilities. Phenolic composition in rice husk extract was analyzed and the mechanism of silver nanoparticle (AgNP) biosynthesis by using AAPE rice husk extract was investigated in this study. Stable and spherically shaped AgNPs with a size of <15 nm were prepared under the following conditions: 0.001 M AgNO3, AAPE rice husk extract diluted 10 times, pH 10, and reacted at 25 °C for 60 min. Synergistic effects among phenolic acids contributed to the formation of AgNPs, with the acids acting as excellent reducing agents (owing to their abundant hydroxyl groups) and excellent dispersants (owing to their derived CO groups), which enhanced the NPs' stability. Caffeic acid (CA) was demonstrated to synthesize AgNPs independently and is suggested to be the most crucial compound for reducing Ag+ during the biosynthesis with rice husk extract. A possible mechanism and reaction process for the formation of AgNPs synthesized using CA in rice husk extracts is proposed.Graphical abstractMechanism and reaction process for the formation of AgNP synthesized using CA in rice husk extracts.

Source: Journal of Food and Drug Analysis - July 11, 2018 Category: Food Science Source Type: research