Hyper-Efficient Quenching of a Conjugated Polyelectrolyte by Dye-Doped Silica Nanoparticles: Better Quenching in the Nonaggregated State
journal contributionposted on 02.02.2010, 00:00 by Chunyan Tan, Yonghua Xie, Xiaoxiao He, Kemin Wang, Yuyang Jiang
We investigated the quenching properties of poly(phenylene ethynylene) with anionic alkoxyl sulfonate side groups, PPE-SO3, by tris(2,2-bipyridyl)dichlororuthenium(II) (Rubpy)-doped silica nanoparticles (SiNPs) in water, methanol, and the surfactant Triton X-100 aqueous solution. SiNPs demonstrated hyper-efficient quenching characterized by the Stern−Volmer constants in the range of 109−1010 M−1, which is about 100−10 000 times more efficient compared to the Rubpy dye. More importantly, quenching by SiNPs was found to be more efficient when the polymer existed as a nonaggregated state, such as in methanol solution and in the surfactant solution. Investigations on confocal fluorescence images and time-resolved fluorescence decays were carried out to study the quenching mechanism.