“Click” on Alkynylated Carbon Quantum Dots: An Efficient Surface Functionalization for Specific Biosensing and Bioimaging

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• 作者：Ming Xuan Gao ; Lin Yang ; Yi Zheng ; Xiao Xi Yang ; Hong Yan Zou ; Jing Han ; Ze Xi Liu ; Prof. Yuan Fang Li and Prof. Cheng Zhi Huang
• 刊名：Chemistry - A European Journal
• 出版年：2017
• 出版时间：February 10, 2017
• 年：2017
• 卷：23
• 期：9
• 页码：2171-2178
• 全文大小：1637K
• ISSN：1521-3765

文摘

Surface functionalization is an essential pre requisite for wide and specific applications of nanoparticles such as photoluminescent (PL) carbon quantum dots (CQDs), but it remains a major challenge. In this report, alkynylated CQDs, prepared from carboxyl-rich CQDs through amidation with propargylamine in the presence of 1,1′-carbonyldiimidazole, were modified efficiently with azido molecular beacon DNA through a copper(I)-catalyzed alkyne–azide cycloaddition reaction (CuAAC). As a proof-of-concept, the DNA-modified CQDs are then bonded with gold nanoparticles (AuNPs, 5 nm) through a gold–sulfur bond. Owing to the emission enhancement, this complex can then be applied to the recognition of a single-base- mismatched target. The same functionalizing strategy applied to click the alkynylated CQDs with a nuclear localization sequence (NLS) peptide showed that the NLS-modified CQDs could target the nuclei specifically. These results indicate that surface functionalization of CQDs through a nonstoichiometric copper chalcogenide nanocrystal- (nsCuCNC-) catalyzed click reaction is efficient, and has significant potential in the fields of biosensing and bioimaging.