J-Aggregate squaraine nanoparticles with bright NIR-II fluorescence for imaging guided photothermal therapy

We introduce a novel strategy to enhance the fluorescence brightness of organic-molecule-based nanoparticles in the second near-infrared window (NIR-II, 1000-1700 nm) by fabricating J-aggregate nanoparticles SQP-NPs(J). Our prepared J-aggregate nanoparticles SQP-NPs(J) show an emission maximum near 1100 nm, and the emission intensity is 4.8-fold higher than that of H-aggregate SQP-NPs(H). In addition, SQP-NPs(J) can be used for NIR-II imaging guided photothermal therapy on MCF-7 tumor-bearing mice due to the fact that SQP-NPs(J) have highly effective photothermal properties, which are significant for precise tumor diagnostics and treatments.