Novel D-π-A Type Near-infrared Fluorescent Probes for the Detection of Aβ40 Aggregates

Aberrant accumulation of Amyloid-β (Aβ) peptide is closely related to Alzheimer´s disease. Thus, it is important to develop featured probes for the specific detection of Aβ species. Herein, we designed and synthesized a novel near-infrared fluorescent probe SDPY based on D-π-A architecture for the detection of Aβ aggregates. The probe SDPY displayed higher affinity towards Aβ40 aggregates over Aβ42 aggregates in solution (Kd =164 nM vs 2.1 μM). In additon, SDPY showed excellent anti-interference against a wide range of other substances. Furthermore, SDPY was capable of labeling better on Aβ40 aggregates than Aβ42 aggregates in the brain sections of AD transgenic mouse models.