Near-Infrared Bodipy based Molecular Rotors for β-Amyloid Imaging In Vivo.

Aβ is one of the important biomarkers for diagnosing Alzheimer's disease. Many near-infrared (NIR) probes based on the donor-π-accepter structure have been developed to detect Aβ. Most reported Aβ probes are based on the N,N-dimethylamino group as the ideal donor, which is one of the widely accepted binding units. The development of new fluorescent probes with new binding units to detect Aβ are urgently required. Therefore, we developed three anchoring molecular rotor electron donors consisting of cyclic amines of different ring sizes of, namely five-membered ring (TPyr), six-membered ring (TPip), and seven-membered ring (THAI). These new anchored molecular rotors were connected to a BODIPY and named TPyrBDP, TPipBDP, and THAIBDP. These probes exhibited high affinities (from 28 nM to 54 nM) for Aβ 1-42 aggregates. The six-membered ring dye TPipBDP exhibited the highest signal-to-noise (75.5-fold) and higher affinity (28.30 ± 5.94 nM). TPipBDP can cross the blood-brain barrier (BBB) and exhibits higher fluorescence enhancement with Tg mice than with wild-type mice. This article is protected by copyright. All rights reserved.