Fluorescent cellulose nanocrystals via supramolecular assembly of terpyridine-modified cellulose nanocrystals and terpyridine-modified perylene

Due to their natural origin, biocompatibility, and non-toxicity, cellulose nanocrystals are promising candidates for applications in nanomedicine. Highly fluorescent nanocellulosic material was prepared via surface modification of cellulose nanocrystals with 2,2':6,2 ''-terpyridine side chains followed by supramolecular assembly of terpyridine-modified perylene dye onto the terpyridine-modified cellulose nanocrystals (CTP) via Ru-III/Ru-II reduction. The prepared terpyridine-modified cellulose-Ru-II-terpyridine-modined perylene (CTP-Ru-II-PeryTP) fluorescent nanocrystals were characterized using cross-polarized/magic angle spin C-13 nuclear magnetic resonance (CP/MAS C-13 NMR), Fourier transform infrared (FTIR). UV-visible, and fluorescence spectroscopy. In addition, further self-assembly of terpyridine units with azide functional groups onto CTP-Ru-II-PeryTP was possible via repeating the Ru-III/Ru-II reduction protocol to prepare supramolecular fluorescent nanocrystals with azide functionality (CTP-Ru-II-PeryTP-Ru-II-AZTP). The prepared derivative may have potential application in bio-imaging since the terminal azide groups can be easily reacted with antigens via Click chemistry reaction. (C) 2012 Elsevier B.V. All rights reserved.