Plant extracts of amla ( Phyllanthus emblica ), tea ( Camellia sinensis ) and coffee ( Coffea ) are prepared and used for the green synthesis of stable gold nanoparticles. The approach is simple, cost effective and environmentally friendly. The various gold nanoparticles (AuNPs-Amla, AuNPs-Tea and AuNPs-Coffee) are characterised by various spectroscopic and microscopic techniques. The borohydride mediated reduction of 4-nitrophenol is used as a model system to study the catalytic activity of the resulting AuNPs. The reaction rates are quite high following the first order kinetics with first order rate constant of 5.4 × 10 −1 min −1 , 8.7 × 10 −1 min −1 , and 2.8 × 10 −1 min −1 respectively for AuNP-amla, AuNP-tea and AuNP-coffee. The in vitro cytotoxicity study by MTT assay reveals that the various green synthesised AuNPs are not cytotoxic to living cells and their IC 50 values towards two ...

中文翻译：

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使用植物提取物合成金纳米颗粒的绿色化学方法：催化和生物学的潜在材料

制备了Amla（余甘子），茶（Camellia sinensis）和咖啡（Coffea）的植物提取物，并将其用于绿色合成稳定的金纳米粒子。该方法简单，经济高效且环保。各种金纳米颗粒（AuNPs-Amla，AuNPs-茶和AuNPs-咖啡）的特征在于各种光谱和显微技术。硼氢化物介导的4-硝基苯酚还原反应用作模型系统来研究所得AuNPs的催化活性。遵循一级动力学的反应速率相当高，对于AuNP-amla，一级速率常数分别为5.4×10 -1 min -1，8.7×10 -1 min -1和2.8×10 -1 min -1， AuNP茶和AuNP咖啡。