Light-controlled fluorescent probes for precisely monitoring brain amyloid-β aggregates in Alzheimer's disease

Alzheimer’s disease (AD) is a neurodegenerative disorder in which the biological fate of amyloid-beta (Aβ) aggregates is a fundamental question. Fluorescent probes as one of the tools for the early diagnosis of Aβ have become very popular in recent years. Although the interactions between light and Aβ formation were studied, light-controlled fluorescent probes for Aβ detection were rarely reported. Herein, the “photo-triggered” strategy was introduced for designing probe PTAD-3 which could detect Aβ aggregates under light irradiation. This probe can rapidly respond to Aβ fibrils in light with high SNR and showed high selectivity to Aβ. Additionally, photo-activated PTAD-3 was able to label Aβ plaques in AD mouse brain slides with excellent colocalization with 6E10 antibody staining. Importantly, the irradiated PTAD-3 has successfully been applied to image Aβ plaques in the live AD mice. As a proof of concept, fluorescent probes based on the “photo-triggered” strategy for Aβ detection were proved to be feasible, which could be applied in the design of light-controlled molecules for the clinical diagnosis and treatment of AD.