Studies on multivalent interactions of quantum dots–protein self-assemble using fluorescence coupled capillary electrophoresis

Autor: Li Jinchen, Chai Hong, Lin Qiu, Wei Hu, Jianhao Wang, Teng Yiwan, Jingyan Li, Pengju Jiang, Wang Cheli
Rok vydání: 2014
Předmět:
Zdroj: Journal of Nanoparticle Research. 16
ISSN: 1572-896X
1388-0764
DOI: 10.1007/s11051-014-2487-y
Popis: Nanoparticle–biomolecules self-assembly is the key to the understanding of biomolecular coating of nanoparticle. However, the self-assembly of biomolecules with nanoparticles is still under-exploited because of the lack of an efficient method to detect the subtle changes in the surface of nanoparticles. In this study, we utilized fluorescence coupled capillary electrophoresis (CE-FL) to probe the binding interaction between a multivalent ligand (dBSA, denatured bovine serum albumin which contains multiple thiol groups) and CdSe/ZnS quantum dots (QDs, 5 nm in diameter). The yield of QDs–dBSA complex increased with increasing molar ratio of dBSA to QDs, which plateaued at a ratio of 8:1. Besides, QDs–dBSA complex showed good stability due to the multivalent interaction, revealing that dBSA is a superior ligand for QDs. The self-assembly kinetics of QDs with dBSA manifested a bi-phasic kinetics with a linear initial stage followed by a saturating stage. This work revealed for the first time that there exist two types of binding sites on the surface of QDs for dBSA: one type termed “high priority” binding sites, which preferentially bind to the protein, whereas the “low priority” sites are occupied only after the first-type binding sites are fully bound. Our work thereby represents the first example of systematic investigation on the details of the metal-affinity driven self-assembly between QDs and dBSA utilizing the high-resolution CE-FL. It also expanded the application of CE-FL in the study of nanoparticle–biomolecule interaction and kinetics analysis.
Databáze: OpenAIRE
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