Holden Megan S, Nick Kevin E, Hall Mia, Milligan Jamie R, Chen Qiao, Perry Christopher C
Department of Basic Sciences, School of Medicine, Loma Linda University, Loma Linda, CA 92350.
Department of Earth and Biological Sciences, School of Medicine, Loma Linda University, Loma Linda, CA 92350.
RSC Adv. 2014;4(94):52279-52288. doi: 10.1039/C4RA07581A.
In this report, we demonstrate a rapid, simple, and green method for synthesizing silver-gold (Ag-Au) bimetallic nanoparticles (BNPs). We used a novel modification to the galvanic replacement reaction by suspending maltose coated silver nanoparticles (NPs) in ≈ 2% aqueous solution of EOPOEO (Pluronic F127) prior to HAuCl addition. The Pluronic F127 stabilizes the BNPs, imparts biocompatibility, and mitigates the toxicity issues associated with other surfactant stabilizers. BNPs with higher Au:Ag ratios and, subsequently, different morphologies were successfully synthesized by increasing the concentration of gold salt added to the Ag NP seeds. These BNPs have enhanced catalytic activities than typically reported for monometallic Au or Ag NPs (∼ 2-10 fold) of comparable sizes in the sodium borohydride reduction of 4-nitrophenol. The 4-nitrophenol reduction rates were highest for partially hollow BNP morphologies.
在本报告中，我们展示了一种快速、简单且绿色的合成银金（Ag-Au）双金属纳米颗粒（BNPs）的方法。我们对原电池置换反应进行了新颖的改进，即在添加HAuCl之前，将麦芽糖包覆的银纳米颗粒（NPs）悬浮于约2%的EOPOEO（普朗尼克F127）水溶液中。普朗尼克F127可稳定BNPs，赋予其生物相容性，并减轻与其他表面活性剂稳定剂相关的毒性问题。通过增加添加到Ag NP种子中的金盐浓度，成功合成了具有更高Au:Ag比率以及随后不同形态的BNPs。在硼氢化钠还原4-硝基苯酚的过程中，这些BNPs比尺寸相当的典型单金属Au或Ag NPs具有更高的催化活性（约2-10倍）。对于部分中空的BNP形态，4-硝基苯酚的还原速率最高。
