Organic dye doped nanoparticles with NIR emission and biocompatibility for ultra-deep in vivo two-photon microscopy under 1040 nm femtosecond excitation

NIR emissive TPABDFN-PSMA-PEG nanoparticles with large two-photon absorption cross-section were intravenously injected into a mouse, and three-dimensional architecture of the blood vessels in the mouse brain was reconstructed vividly with two-photon fluorescence microscopy at imaging depth ∼1200 μm.291