Unimolecular Organic Afterglow Luminophore With Anti‐Kasha/Kasha Emission for in Vivo Activatable Imaging

/sr, which is nearly three orders of magnitude higher than previously reported unimolecular organic afterglow probes. Leveraging the structural flexibility, a butyrylcholinesterase (BChE)-activatable afterglow probe (CyIAB-T) is fabricated. This probe enables a specific and sensitive detection of BChE in Alzheimer's disease (AD) model mice with higher contrast relative to fluorescence imaging. Importantly, this probe permits dynamic tracking of the age-dependent upregulation of BChE during AD progression. Therefore, this study establishes a versatile unimolecular organic afterglow scaffold with high intensity and structural flexibility for developing activatable afterglow probes for high-contrast biomedical imaging.