A Precipitation‐Enhanced Emission (PEE) Strategy for Increasing the Brightness and Reducing the Liver Retention of NIR‐II Fluorophores (Small 49/2022)

NIR-II Fluorophores In article number 2204153, Weimin Liu, Jianfeng Li, and co-workers propose a strategy of precipitation-enhanced emission (PEE). The PEE is realized by combining NIR-II fluorophores named LJ-2P with calcium ions to form LJ-2P nanoparticles (NPs). LJ-2P NPs form a cavity surrounding LJ-2P molecules, which effectively reduces the molecular rotation and interaction of water molecules. These together increase the radiative transition, which leads to enhanced quantum yields (QYs) of LJ-2P NPs in aqueous solution by 36.57-fold. This strategy can be applied to other NIR-II molecules as a general strategy to improve QYs.