Single-Pot Biofabrication of Zinc Sulfide Immuno-Quantum Dots
Single-Pot Biofabrication of Zinc Sulfide Immuno-Quantum Dots
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DOI：
10.1021/ja909406n
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发表时间：
2010-04-07
影响因子：
15
通讯作者：
Baneyx, Francois
中科院分区：
文献类型：
--
作者：
Zhou, Weibin;Schwartz, Daniel T.;Baneyx, Francois
量子点是有机染料和荧光蛋白在生物和生物医学应用中的一种强有力的替代品。这些半导体纳米晶体传统上是在200摄氏度以上的有机溶剂中使用有毒且昂贵的前体合成的，需要进一步的步骤才能将它们连接到生物配体上。在这里，我们描述了一种简单的水溶液一锅法合成抗体衍生的硫化锌免疫量子点。在该策略中，易于表达和纯化的融合蛋白具有纳米晶矿化剂的双重功能，通过细胞表面显示鉴定的锌结合序列，以及通过金黄色葡萄球菌蛋白A的B结构域的串联重复来连接免疫球蛋白G(IgG)的接头。尽管氯化锌或醋酸锌前体可以生物矿化约4.3 nm的纤锌矿核心，但只有后者的盐能产生长货架期和窄流体动力学直径(8.8+/-1.4 nm)的蛋白包裹的量子点。生物富集化的量子点具有2.5%的量子产率和蓝绿整体发射，贡献来自340 nm的带边和460和665 nm的陷阱态，这些贡献受到蛋白质壳层特性的影响。小鼠免疫球蛋白(1)抗体对蛋白壳层具有很高的亲和力(K-d=60 nm)，将生物微球与人免疫球蛋白混合，可得到流体力学直径为14.1+/-1.3 nm的稳定免疫量子点。
Quantum dots (QDs) are a powerful alternative to organic dyes and fluorescent proteins for biological and biomedical applications. These semiconductor nanocrystals are traditionally synthesized above 200 degrees C in organic solvents using toxic and costly precursors, and further steps are required to conjugate them to a biological ligand. Here, we describe a simple, aqueous route for the one-pot synthesis of antibody-derivatized zinc sulfide (ZnS) immuno-QDs. In this strategy, easily expressed and purified fusion proteins perform the dual function of nanocrystal mineralizers through ZnS binding sequences identified by cell surface display and adaptors for immunoglobin G (IgG) conjugation through a tandem repeat of the B domain of Staphylococcus aureus protein A. Although approximate to 4.3 nm ZnS wurtzite cores could be biomineralized from either zinc chloride or zinc acetate precursors, only the latter salt gives rise to protein-coated QDs with long shelf life and narrow hydrodynamic diameters (8.8 +/- 1.4 nm). The biofabricated QDs have a quantum yield of 2.5% and blue-green ensemble emission with contributions from the band-edge at 340 nm and from trap states at 460 and 665 nm that are influenced by the identity of the protein shell. Murine IgG(1) antibodies exhibit high affinity (K-d = 60 nM) for the protein shell, and stable immuno-QDs with a hydrodynamic diameter of 14.1 +/- 1.3 nm are readily obtained by mixing biofabricated nanocrystals with human IgG.