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

淀粉样β（Aβ）聚集物在大脑中的沉积是受阿尔茨海默氏病（AD）影响的大脑的标志。在聚集过程中会产生各种聚集的Aβ物种，包括低聚物和原纤维，并且这些Aβ聚集体具有独特的生物学特性。为了无创地监测Aβ的聚集途径并确定生物环境中某些Aβ物种的存在，必须有一种有效的策略来检测Aβ物种。在此，我们报告了Aβ聚集体的开启式近红外（near-IR）荧光探针1，该探针由具有Aβ相互作用部分的供体-π-受体系统组成。我们的探针1显示了在大约200 nm处的近红外荧光显着增加。在水性介质中，在Aβ聚集的情况下710 nm。另外，取决于Aβ聚集的程度，改变了1的荧光响应。此外，1表示活细胞中Aβ聚集的开启荧光，并且在用于活细胞成像的条件下无毒。