We report on a novel and simple approach to surface ligand design of CdSe-based nanocrystals (NCs) with biocompatible, heterobifunctional polyethylene glycol (PEG) molecules. This method provides high transfer yields of the NCs into aqueous media with preservation of the narrow and symmetric emission bands of the initial organic-capped NCs regardless of their interior crystal structure and surface chemistry. The PEG-functionalized NCs show small sizes, high photoluminescence quantum yields of up to 75%, as well as impressive optical and colloidal stability. This universal approach is applied to different fluorescent nanomaterials (CdSe/CdS, CdSe/CdSCd_xZn_1–xS, and CdSe/CdS/ZnS), extending the great potential of organic-capped NCs for biological applications.

中文翻译：

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无机封端的纳米晶体转移到水性介质中

我们报告了一种新颖，简单的方法与生物相容性，异双功能聚乙二醇（PEG）分子的基于CdSe的纳米晶体（NCs）的表面配体设计。这种方法可将NC转移到水性介质中的产率很高，并且保留了初始有机封端NC的窄且对称的发射带，而不论其内部晶体结构和表面化学性质如何。PEG官能化的NCs体积小，高达75％的高光致发光量子产率以及出色的光学和胶体稳定性。这种通用方法适用于不同的荧光纳米材料（CdSe / CdS，CdSe / CdSCd _x Zn _{1- x} S和CdSe / CdS / ZnS），从而扩展了有机盖帽的NC在生物学应用中的巨大潜力。