Organic Long Persistent Luminescence Aqueous Dispersion

ABSTRACT

Organic long persistent luminescence (OLPL) materials with long afterglow duration are promising for biomedicine, but the fabrication of aqueous OLPL dispersion remains challenging due to the water/oxygen quenching. Here we report aqueous OLPL dispersions via a donor‐sensitizer‐acceptor (DSA) three‐component strategy. A difluoroboron β‐diketonate (BF ₂ bdk) photosensitizers, combined with N,N,N',N'‐ tetramethylbenzidine (TMB, an electron donor) and phenyl 4‐methoxybenzoate (MeOPhB, an electron acceptor and also organic matrix), form solid‐state OLPL materials with hours‐long afterglow duration (>2.5 h) and visible‐light‐excitation characteristics. Leveraging MeOPhB's moderate melting point (74°C), the solid‐state materials can be facilely processed into aqueous dispersions with the aid of surfactants. Spectroscopy fluorescence microscope system confirms the crystalline nature of the OLPL microparticles in aqueous dispersion and enables in situ collection of their emission spectra. The aqueous OLPL dispersions retain characteristic power‐law emission decay and exhibit significant afterglow in water, with the crystalline MeOPhB matrix shielding charge‐separated states from quenching. Preliminary bioimaging in live fish shows clear, background‐free afterglow, eliminating autofluorescence interference. This work fills the aqueous OLPL gap and provides a general strategy for translating solid‐state OLPL to water‐based systems, paving the way for high‐contrast in vivo imaging applications.