Biosynthesis of Silver Nanoparticles Using Rice Husk Extracts

• Main Authors: Lieu Yee Shing, 劉苡杏
• Other Authors: Hui-Huang Chen
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/4966tv

碩士 === 國立宜蘭大學 === 食品科學系碩士班 === 103 === Phenolic acids are the major bioactive compounds responsible for the reducing abilities of rice husk. The phenolic acids profiles, total phenolic content (TPC), reducing power and ferric-reducing antioxidant power (FRAP) assays of rice husk extracts those using boiling water extraction (BWE) and combined acid and alkali pretreatment extraction (AAPE) were quantified in this study. The effects of experimental parameters such as pH, volume ratio of rice husk extract and silver nitrate, incubation temperature, concentration of extracts and silver nitrate on the formation of silver nanoparticles were studied. AAPE produced higher total phenolic content (3,428 mg GAE/100 g husk in TPC result, 1,525 mg/100 g husk in HPLC results) in extract and possessed stronger reducing abilities (FRAP and reducing power is 1,433 mM FeSO4/g husk and 980 times high of 0.002 M NaBH4) than that with BWE (33 mg GAE/100 g husk in TPC, 12 mM FeSO4/g husk in FRAP, 270 times higher than 0.002 M NaBH4). A green synthesis of stable, highly crystalline, spherical-shaped silver nanoparticles with size ＜15 nm was prepared under the following conditions: volume ratio of diluted combined acid and alkali pretreatment rice husk extract with pH 10 and silver nitrate is 1:3, using rice husk extracts has been demonstrated. Caffeic acid has the ability to synthesize silver nanoparticles independently. These results proved the capability of using biomaterial and revealed a potential application in the use of agricultural waste material as an important source of reducing agent in biosynthesis of silver nanoparticles.