Molecular mechanism of the enhancing of AIE effect by human serum albumin

To address the challenge of effective aggregation of aggregation-induced emission (AIE) molecules in biological systems, the study selected four AIE molecules with the same electron acceptor but different electron donors and alkyl side chains, and employed fluorescence spectroscopy, molecular docking techniques and electrochemical analysis to explore systematically the interaction between AIE molecules and HSA and elucidate the key role of HSA in activating AIE fluorescence and its impact on AIE effects. The research has shown that these AIE molecules are unstable and emit weak light in Tris-HCl buffer solution due to their propeller-like flexible structure, but their fluorescence intensity significantly increases by 40-309 times when combined with HSA. In addition, the binding products of AIE molecules and HSA exhibit excellent biocompatibility and can achieve highresolution imaging of cells and kidneys. These findings not only enhance our understanding of the in vivo luminescence mechanism of AIE materials but also provide an experimental basis for the application of AIE materials in biological imaging technology.