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

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