• • TPACN exhibits a fluorescence peak at 1086 nm with a fluorescence quantum yield of 1.55% in DCM, representing a marked red-shift and enhanced emission for aza-BODIPY dyes, which is critical for deep-tissue imaging.
• • TPACN NPs in aqueous solution maintain a FLQY of 0.20% and achieve a photothermal conversion efficiency (PCE) of 39% under 808 nm irradiation, demonstrating a synergistic balance between radiative and non-radiative decay for dual-modal imaging and photothermal therapy.
• • The introduction of triphenylamine (TPA) donors and cyano (–CN) acceptors strengthens intramolecular charge transfer (ICT), broadening NIR absorption and enabling excitation at 808 nm, a wavelength with deeper tissue penetration.
• • The sterically twisted TPA units effectively alleviate aggregation-caused quenching (ACQ), preserving fluorescence in the nanoparticle formulation, which is essential for in vivo imaging and therapeutic efficacy.