文献类型：期刊文献

英文题名：High-Quality Water-Soluble Core/Shell/Shell CdSe/CdS/ZnS Quantum Dots Balanced by Ionic and Nonionic Hydrophilic Capping Ligands

作者：Liu, Lu[1,2];Xu, Hu[3];Shen, Bing[4];Zhong, Xinhua[4]

机构：[1]Univ Shanghai Sci & Technol, Coll Sci, Shanghai 200093, Peoples R China;[2]East China Univ Sci & Technol, Inst Appl Chem, Shanghai 200237, Peoples R China;[3]Shanghai Inst Technol, Sch Chem & Environm Engn, Shanghai 201418, Peoples R China;[4]East China Univ Sci & Technol, Shanghai 200237, Peoples R China

年份：2016

卷号：11

期号：7

外文期刊名：NANO

收录：;EI(收录号：20162002372715);WOS:【SCI-EXPANDED(收录号:WOS:000381102300002)】；

基金：We thank the National Natural Science Foundation of China (No. 21301033), Postdoctoral Science Foundation of China (2015M580339), Shanghai Natural Science Foundation (No. 13ZR1429400), the Fundamental Research Funds for the Central Universities, the Program for Professor of Special Appointment at Shanghai Institutions of Higher Learning for financial support.

语种：英文

外文关键词：Quantum dots; hydrophilic oligomer; ligand exchange; poly(ethylene glycol); poly(acrylic acid)

摘要：Pentaerythritol tetrakis 3-mercaptopropionate (PTMP) grafted poly(acryl acid) (PAA) ionic hydrophilic oligomer PAA-PTMP (PP) and dihydrolipoic acid (DHLA) grafted methoxypoly (ethylene glycol) (mPEG) nonionic hydrophilic oligomer mPEG-DHLA (PD) have been designed, synthesized and used as co-capping ligands in water-solubilization of hydrophobic quantum dots (QDs) via ligand exchange. The obtained oligomers with multi-thiol groups could bind strongly to the surface atoms of QDs. Meanwhile, the carboxyl groups (from PP) and mPEG segment (from PD) can render QDs water-soluble, and the free carboxylic groups can possibly be used for the further bioconjugation. The resulting water-soluble QDs have been characterized by ultraviolet-visible (UV-Vis), fluorescence, Fourier transform infrared (FTIR) spectroscopy as well as transmission electron microscopy (TEM) and dynamic light scattering (DLS) techniques. The water-soluble QDs have relatively small hydrodynamic size (10 - 12 nm), and importantly, retain high fluorescence quantum yields (up to 45%) compared with that of the originally hydrophobic QDs (49%). In addition, they have tunable surface charges and show excellent colloidal stability over a relatively broad pH range (2 - 13), in high salt concentration, and even after thermal treatment at 100 degrees C. These results indicate that the water-soluble QDs coated by PP and PD oligomers have potential applications in cellular imaging and biosensor.