Conjugated polyelectrolyte-grafted silica microspheres

A direct method for preparation of conjugated polymer-grafted silica particles is reported. Silica particles (0.3 and 5 μm diameter) are treated with a 3-(trimethoxysilyl)propylamine derivative that is functionalized with an aryl iodide unit. A solution step-growth polymerization reaction is performed in solution that contains a dispersion of the aryl iodide-functionalized particles. The reaction is a Pd(0)-catalyzed (Sonogashira) A-B-type polymerization of an oligo-(ethylene glycol)-fuctionalized diiodobenzene and a bis(propyloxy)sulfonate-substituted diethynylbenzene. The overall process affords silica particles that feature a surface graft layer of an anionic poly(phenylene ethynylene)-type conjugated polyelectrolyte. The particle surface modification process was monitored by infrared (FTIR) spectroscopy, and the polymer-grafted silica particles were characterized by thermogravimetric analysis, scanning and transmission electron microscopy, confocal fluorescence microscopy, and absorption and fluorescence spectroscopy. The conjugated polyelectrolyte-grafted silica particles are highly fluorescent, and a Stern-Volmer quenching study of the particles' fluorescence with electron-transfer- and energy-transfer-type quenchers shows that the quenching response depends on the type of quenching mechanism. © 2007 American Chemical Society.

Full Text

Duke Authors

Cited Authors

  • Ogawa, K; Chemburu, S; Lopez, GP; Whitten, DG; Schanze, KS

Published Date

  • 2007

Published In

Volume / Issue

  • 23 / 8

Start / End Page

  • 4541 - 4548

International Standard Serial Number (ISSN)

  • 0743-7463

Digital Object Identifier (DOI)

  • 10.1021/la0630108