Synthesis of PEG-grafted boron doped Si nanocrystals.
Synthesis of PEG-grafted boron doped Si nanocrystals.
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DOI：
10.1063/1.5128608
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发表时间：
2019-12
期刊：
影响因子：
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通讯作者：
Jesse R Greenhagen;Himashi P. Andaraarachchi;Zhaohan Li;U. Kortshagen
中科院分区：
文献类型：
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作者：
Jesse R Greenhagen;Himashi P. Andaraarachchi;Zhaohan Li;U. Kortshagen
硅纳米晶体因其独特的光学特性和生物相容性而成为生物医学成像应用中令人感兴趣的材料。我们报告了一种新的表面功能化途径，通过表面硼掺杂来合成生物缓冲液可溶且胶体稳定的硅纳米晶体。利用独特的路易斯酸性硼表面位点，在光化学条件下用聚乙二醇（PEG-OH）配体在二甲亚砜中对等离子体合成的硼掺杂纳米晶体进行后合成修饰。研究了 PEG 浓度、PEG 分子量和硼掺杂百分比对纳米晶体在生物缓冲液中溶解度的影响。硼掺杂通过两种可能的途径促进表面功能化，即在极性溶剂中提供优异的初始分散性并提供可用于键合的酸性硼表面位点。这些硼掺杂硅纳米晶体具有与本征硅纳米晶体几乎相同的吸收特性，表明它们是生物成像应用的有希望的候选者。
Silicon nanocrystals are intriguing materials for biomedical imaging applications because of their unique optical properties and biological compatibility. We report a new surface functionalization route to synthesize biological buffer soluble and colloidally stable silicon nanocrystals, which is enabled by surface boron doping. Harnessing the distinctive Lewis acidic boron surface sites, postsynthetic modifications of plasma synthesized boron doped nanocrystals were carried out with polyethylene glycol (PEG-OH) ligands in dimethyl sulfoxide under photochemical conditions. The influence of PEG concentration, PEG molecular weight, and boron doping percentage on the nanocrystal solubility in a biological buffer has been investigated. The boron doping facilitates the surface functionalization via two probable pathways, by providing excellent initial dispersiblity in polar solvents and providing available acidic boron surface sites for bonding. These boron doped silicon nanocrystals have nearly identical absorption features as intrinsic silicon nanocrystals, indicating that they are promising candidates for biological imaging applications.