Ultrabright Fluorescent Organic Nanoparticles Based on Small-Molecule Ionic Isolation Lattices*.

Ultrabright fluorescent nanoparticles (NPs) hold great promise for demanding bioimaging applications. Recently, extremely bright molecular crystals of cationic fluorophores were obtained by hierarchical coassembly with cyanostar anion-receptor complexes. These small-molecule ionic isolation lattices (SMILES) ensure spatial and electronic isolation to prohibit aggregation quenching of dyes.

Simultaneous Increase in Brightness and Singlet Oxygen Generation of an Organic Photosensitizer by Nanocrystallization.

Efficient organic photosensitizers are attractive for cancer cell ablation in photodynamic therapy. Bright fluorescent photosensitizers are highly desirable for simultaneous imaging and therapy. However, due to fundamental competition between emission and singlet oxygen generation, design attempts to increase singlet oxygen generation almost always leads to the loss of fluorescence.

Organic Nanocrystals with Bright Red Persistent Room-Temperature Phosphorescence for Biological Applications.

Persistent room-temperature phosphorescence (RTP) in pure organic materials has attracted great attention because of their unique optical properties. The design of organic materials with bright red persistent RTP remains challenging. Herein, we report a new design strategy for realizing high brightness and long lifetime of red-emissive RTP molecules, which is based on introducing an alkoxy spacer between the hybrid units in the molecule.

Nanocrystallization: A Unique Approach to Yield Bright Organic Nanocrystals for Biological Applications.

A new bottom-up nanocrystallization method is developed to fabricate highly fluorescent organic nanocrystals in aqueous media using an aggregation-induced emission fluorogen (AIEgen) as an example. The nanocrystallization strategy leads to the fabrication of uniform nanocrystals of 110 ± 10 nm size in aqueous media, which shows over 400% increase in brightness as compared to the amorphous nanoaggregates.

Decoration of porphyrin with tetraphenylethene: converting a fluorophore with aggregation-caused quenching to aggregation-induced emission enhancement.

Porphyrins have long been used as fluorescence imaging contrast agents. However, they often suffer from aggregation-caused quenching (ACQ) which limits their maximal imaging ability. It is desirable to design new porphyrin derivatives exhibiting aggregation induced emission enhancement (AIEE) with a high photoluminescence (PL) intensity in an aggregated state.