Aggregation-enhanced fluorescence in organically modified silica nanoparticles: A novel approach toward high-signal-output nanoprobes for two-photon fluorescence bioimaging

Phase-separated nanoaggregation of a highly loaded 9,10-bis[4'-(4-aminostyryl)styryl]anthracene dye in organically modified silica (ORMOSIL) nanoparticles boosts intracellular two-photon fluorescence signal by virtue of enhanced two-photon absorption and emission, high chromophore number density in the nano-space, and noninvasive cellular uptake.