Fabrication of fluorescent silica nanoparticles hybridized with AIE luminogens and exploration of their applications as nanobiosensors in intracellular imaging.

Highly emissive inorganic-organic nanoparticles with core-shell structures are fabricated by a one-pot, surfactant-free hybridization process. The surfactant-free sol-gel reactions of tetraphenylethene- (TPE) and silole-functionalized siloxanes followed by reactions with tetraethoxysilane afford fluorescent silica nanoparticles FSNP-1 and FSNP-2, respectively. The FSNPs are uniformly sized, surface-charged and colloidally stable. The diameters of the FSNPs are tunable in the range of 45-295 nm by changing the reaction conditions. Whereas their TPE and silole precursors are non-emissive, the FSNPs strongly emit in the visible vision, as a result of the novel aggregation-induced emission (AIE) characteristics of the TPE and silole aggregates in the hybrid nanoparticles. The FSNPs pose no toxicity to living cells and can be utilized to selectively image cytoplasm of HeLa cells.