“Shine & Click” Photo-Induced Interfacial Unmasking of Strained Alkynes on Small Water-Soluble Gold Nanoparticles
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- 作者：Wilson Luo ; Dr. Pierangelo Gobbo ; Christopher D. McNitt ; Dewey A. Sutton ; Prof. Vladimir V. Popik and Prof. Mark S. Workentin
- 刊名：Chemistry - A European Journal
- 出版年：2017
- 出版时间：January 23, 2017
- 年：2017
- 卷：23
- 期：5
- 页码：1052-1059
- 全文大小：5124K
- ISSN：1521-3765
文摘
In this study, we report the design, synthesis, and characterization of small 3 nm water soluble gold nanoparticles (AuNPs) that feature cyclopropenone-masked strained alkyne moieties capable of undergoing interfacial strain-promoted cycloaddition (i-SPAAC) with azides after exposure to UV-A light. A strained alkyne precursor was incorporated onto AuNPs by direct ligand exchange of a thiol-modified cyclopropenone-masked dibenzocyclooctyne (photoDIBO) ligand. These photoDIBO-AuNPs were characterized by 1H NMR, IR, and UV/Vis spectroscopy, as well as transmission electron microscopy (TEM) and thermogravimetric analysis (TGA), and the extent of modification was quantified. Upon irradiation with UV-A light, photoDIBO-AuNPs underwent efficient and quantitative regeneration of the parent strained alkyne by photochemical decarbonylation to afford DIBO-derivatized AuNPs. DIBO-AuNPs were found to react cleanly and rapidly (k=5.3×10−2 m−1 s−1) by an interfacial strain-promoted alkyne-azide cycloadditon (i-SPAAC) with benzyl azide, which served as a simple model system. Furthermore, DIBO-AuNPs were reacted with various azides and a nitrone (interfacial strain-promoted alkyne-nitrone cycloaddition, i-SPANC) to showcase the generality of this approach for the facile modification of AuNP surfaces and their properties. The cyclopropenone-based photo-triggered click chemistry at the interface of water-soluble AuNPs offers exciting opportunities for the atom-by-atom control and assembly of functional materials for applications in materials and biomaterials science as well as in chemical biology.