title: "Click" on Alkynylated Carbon Quantum Dots: An Efficient Surface Functionalization for Specific Biosensing and Bioimaging.
abstract: 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.
authors.affiliation: Education Ministry Key Laboratory on Luminescence and Real-Time Analysis Chemistry, College of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, P.R. China.
authors.forename: Ming Xuan
authors.initials: MX
authors.lastname: Gao
authors.affiliation: College of Pharmaceutical Sciences, Southwest University, Chongqing, 400715, P. R. China.
authors.forename: Lin
authors.initials: L
authors.lastname: Yang
authors.affiliation: Department of Endocrinology, Xinqiao Hospital, Third Military Medical University, Chongqing, 400037, P.R. China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zheng
authors.affiliation: College of Pharmaceutical Sciences, Southwest University, Chongqing, 400715, P. R. China.
authors.forename: Xiao Xi
authors.initials: XX
authors.lastname: Yang
authors.affiliation: College of Pharmaceutical Sciences, Southwest University, Chongqing, 400715, P. R. China.
authors.forename: Hong Yan
authors.initials: HY
authors.lastname: Zou
authors.affiliation: College of Pharmaceutical Sciences, Southwest University, Chongqing, 400715, P. R. China.|Present address: Institute of Chemistry, Chinese Academy of Science, Beijing, 100190, P. R. China.
authors.forename: Jing
authors.initials: J
authors.lastname: Han
authors.affiliation: College of Pharmaceutical Sciences, Southwest University, Chongqing, 400715, P. R. China.
authors.forename: Ze Xi
authors.initials: ZX
authors.lastname: Liu
authors.affiliation: Education Ministry Key Laboratory on Luminescence and Real-Time Analysis Chemistry, College of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, P.R. China.
authors.forename: Yuan Fang
authors.initials: YF
authors.lastname: Li
authors.affiliation: Education Ministry Key Laboratory on Luminescence and Real-Time Analysis Chemistry, College of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, P.R. China.|College of Pharmaceutical Sciences, Southwest University, Chongqing, 400715, P. R. China.
authors.forename: Cheng Zhi
authors.initials: CZ
authors.lastname: Huang
mesh_terms: D000480:Alkynes / Q000737:chemistry; D001386:Azides / Q000737:chemistry; D015374:Biosensing Techniques; D002244:Carbon / Q000737:chemistry*; D002384:Catalysis; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D057930:Click Chemistry; D003300:Copper / Q000737:chemistry; D061565:Cycloaddition Reaction; D004247:DNA / Q000032:analysis* / Q000737:chemistry; D000067493:Dynamic Light Scattering; D006046:Gold / Q000737:chemistry; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry; D018613:Microscopy, Confocal; D045663:Quantum Dots / Q000737:chemistry* / Q000378:metabolism / Q000633:toxicity; D013499:Surface Properties
chemical_list: D000480:Alkynes; D001386:Azides; D002244:Carbon; D006046:Gold; D003300:Copper; D004247:DNA
keywords: DNA; carbon quantum dots; click chemistry; peptides; surface functionalization