Minimizing nonspecific cellular binding of quantum dots with hydroxyl-derivatizied surface coatings
Minimizing nonspecific cellular binding of quantum dots with hydroxyl-derivatizied surface coatings
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DOI：
10.1021/ac800068q
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发表时间：
2008-04-15
影响因子：
7.4
通讯作者：
Nie, Shuming
中科院分区：
文献类型：
--
作者：
Kairdolf, Brad A.;Mancini, Michael C.;Nie, Shuming
量子点（QD）纳米晶体是一种很有前途的荧光探针，可用于生物多路染色分析。然而，与细胞膜和蛋白质结合的非特异性QD仍然是检测灵敏度和特异性的限制因素。在这里，我们报道了一类新的羟基（-OH）涂层量子点，以最大限度地减少非特异性细胞结合，并克服了以前表面涂层遇到的体积庞大的问题。羟基化量子点是由羧基化（-COOH）点通过羟基化和交联过程制备的。它们具有13-14 nm（直径）的紧凑流体动力学尺寸，具有高荧光（bbb60 %的量子产率），并且在碱性和酸性条件下都很稳定。通过使用人类癌细胞，我们已经评估了它们与羧基化、蛋白包被和聚乙二醇包被的量子点的优越的非特异性结合特性。定量细胞染色数据表明，羟基化量子点导致非特异性结合相对于羧化量子点显著减少140倍，相对于PEG和蛋白质包被量子点仍然显著减少10-20倍。
Quantum-dot (QD) nanocrystals are promising fluorescent probes for multiplexed staining assays in biological applications. However, nonspecific QD binding to cellular membranes and proteins remains a limiting factor in detection sensitivity and specificity. Here we report a new class of hydroxyl (-OH)-coated QDs,for minimizing nonspecific cellular binding and for overcoming the bulky size problems encountered with previous surface coatings. The hydroxylated QDs are prepared from carboxylated (-COOH) dots via a hydroxylation and cross-linking process. With a compact hydrodynamic size of 13-14 nm (diameter), they are highly fluorescent (> 60% quantum yields) and stable under both basic and acidic conditions. By using human cancer cells, we have evaluated their superior nonspecific binding properties against that of carboxylated, protein-coated, and poly(ethylene glycol) (PEG)-coated QDs. Quantitative cellular staining data indicate that the hydroxylated QDs result in a dramatic 140-fold reduction in nonspecific binding relative to that of carboxylated dots and-a still significant 10-20-fold reduction relative to that of PEG- and protein-coated dots.