Seedless, surfactantless, high-yield synthesis of branched gold nanocrystals in HEPES buffer solution
Seedless, surfactantless, high-yield synthesis of branched gold nanocrystals in HEPES buffer solution
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DOI：
10.1021/cm0700100
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发表时间：
2007-05-29
影响因子：
8.6
通讯作者：
Wang, Daniel I. C.
中科院分区：
文献类型：
--
作者：
Xie, Jianping;Lee, Jim Yang;Wang, Daniel I. C.
在本工作中，通过将氯金酸的水溶液与Good的缓冲液HEPES在室温下反应，高产率地制备了三维支化金纳米晶体。这种特殊的制备方法可以扩展到克量。含有1-8个尖端的支化纳米晶在室温下是稳定的，冷冻干燥后可以作为粉末储存。然而，它们在较高的温度下不稳定，在沸腾时转化为球形颗粒。分枝金纳米晶的形成受动力学控制，其形状随温度和前驱体盐浓度的变化而变化。利用显微镜和光谱技术对HEPES缓冲液中支化金纳米晶体的生长进行了监测，从而能够检测到生长过程中的几个关键中间体。HEPES分子中的哌嗪被确定为在HEPES缓冲液中形成高度支化的Au纳米晶的主要部分。
In this work, three-dimensional branched gold nanocrystals were produced at high yield by reacting an aqueous solution of chloroauric acid with a Good's buffer, HEPES, at room temperature. This particular method of preparation was scalable to gram-quantity. The branched nanocrystals containing one to eight tips were stable at room temperature and could be stored as a powder after freeze-drying. They were, however, unstable at higher temperatures and transformed into spherical particles upon boiling. The formation of the branched gold nanocrystals was kinetically controlled, as shown by the dependence of shapes on temperature and precursor salt concentration. The growth of branched gold nanocrystals in the HEPES buffer was monitored by microscopic and spectroscopic techniques, allowing the detection of several key intermediates in the growth process. Piperazine in HEPES molecule was identified as the principal moiety responsible for forming highly branched Au nanocrystals in the HEPES buffer.