Spontaneous growth of gold nanoclusters to form gold nanoparticles in the presence of high molecular weight poly(ethylene glycol)
Spontaneous growth of gold nanoclusters to form gold nanoparticles in the presence of high molecular weight poly(ethylene glycol)
复制标题
DOI：
10.1016/j.colsurfa.2019.124113
复制
发表时间：
2020-01
期刊：
影响因子：
--
通讯作者：
N. Uehara;Natsumi Sonoda;T. Iwamatsu;Chikara Haneishi;Arinori Inagawa
中科院分区：
文献类型：
--
作者：
N. Uehara;Natsumi Sonoda;T. Iwamatsu;Chikara Haneishi;Arinori Inagawa
金属纳米粒子的制备方法简单、方便，一直是纳米技术中需要克服的挑战性问题。为了解决这一问题，在环境条件下研究了在高分子量聚乙二醇（PEG）存在下金纳米团簇自发生长以形成金纳米颗粒。只有在分子量至少为2 × 106 g/mol的结构有序的PEG存在下，粒径为1.2 nm的金纳米团簇才会自发生长形成在520 nm处具有等离子体吸收带的更大的金纳米颗粒，产生粉红色溶液。紫外-可见吸收光谱表明，存在两个步骤负责金纳米团簇的生长，形成金纳米粒子。第一步涉及由于金纳米团簇的聚集，在前10分钟期间在520 nm处的光谱带的吸光度增加。第二个步骤是在相同的波长下，由于融合，接着是金纳米团簇的生长，该带变宽。氧化还原电位和透射电子显微镜（TEM）的图像显示，结构上有组织的高分子量PEG诱导聚集的金纳米团簇和随后的生长，形成更大的纳米粒子，表现出板状三角形结构与尖锐的边缘。我们的研究揭示了PEG在金纳米团簇到金纳米颗粒生长过程中的作用。
Simple and convenient preparation of metal nanoparticles has been a challenging issue to overcome in nano-technologies. To address this, spontaneous growth of gold nanoclusters to form gold nanoparticles in the presence of high molecular weight poly(ethylene glycol) (PEG) was studied under ambient conditions. Gold nanoclusters with a particle size of ∼2 nm spontaneously grew to form larger gold nanoparticles with a plasmonic absorption band at 520 nm only when in the presence of structurally organized PEG with a molecular weight of at least 2 × 106g/mol, producing a pinkish colored solution. UV–vis absorption spectra indicate the existence of two steps responsible for gold nanocluster growth to form gold nanoparticles. The first step involves an increase in the absorbance of the spectral band at 520 nm during the first 10 min due to aggregation of gold nanoclusters. The second step is the broadening of this band at the same wavelength as a result of fusion followed by growth of the gold nanoclusters. Redox potentials and transmission electron microscopy (TEM) images reveal that structurally organized high molecular weight PEG induces aggregation of the gold nanoclusters and their subsequent growth to form larger nanoparticles, which exhibit plate-like triangular structures with sharp edges. Our study unveils the role that PEG plays in the growth process from gold nanoclusters to gold nanoparticles.