A near-infrared fluorescent probe for amyloid-beta aggregates

摘要

The deposition of amyloid-beta (A beta) aggregates in the brain is a hallmark of the Alzheimer's disease (A beta)-affected brain. Various aggregated A beta species, including oligomers and fibrils, are generated upon the aggregation process, and these A beta aggregates have distinct biological properties. To non-invasively monitor the aggregation pathways of A beta and identify the existence of certain A beta species in biological environments, an effective strategy to detect A beta species is necessary. Herein, we report a turn-on near-infrared (near-IR) fluorescent probe, 1, for A beta aggregates, which consists of a donor-pi-acceptor system with an A beta-interacting moiety. Our probe, 1, shows a noticeable increase in near-IR fluorescence at ca. 710 run in the presence of A beta aggregates in aqueous media. In addition, the fluorescent response of 1 was altered depending on the degree of A beta aggregation. Moreover, 1 indicates turn-on fluorescence with A beta aggregates in living cells and is nontoxic under the condition used for live-cell imaging.