Investigations into tau-targeting diagnosis of Alzheimer's disease are currently underway, and the development of tau-selective molecular probes is urgently required. In this study, the donor-π-acceptor architecture of the previously reported tau-selective fluorescence probe was modified into thiophene-π-cyanoacetamides. While the fluorescence properties of the prepared probes were not influenced by the thiophene substituents, intense and tau-selective turn-on fluorescence in the near infrared region was observed only in the probes with unsubstituted phenyl or p-methylphenyl cyanoacetamides in the acceptor functionality. Compared with the parent compound, the newly identified probes showed 1.5 ∼ 4.1 times increase in tau-selectivity over Aβ fibrils and 3.5 ∼ 4.7 times increase in fluorescence intensity. The tau-selective fluorescence properties of the title probes were further demonstrated in the cellular milieu, and the green and red fluorescence emitted by GFP and tau-bound probes, respectively, were shown to be nicely colocalized in the SH-SY5Y cells stably expressing GFP-tagged tau.

中文翻译：

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噻吩-π-氰基乙酰胺在近红外区域显示出强烈的 Tau 选择性开启荧光

目前正在进行阿尔茨海默病 tau 靶向诊断的研究，迫切需要开发 tau 选择性分子探针。在这项研究中，先前报道的 tau 选择性荧光探针的供体-π-受体结构被修饰成噻吩-π-氰基乙酰胺。虽然制备的探针的荧光性质不受噻吩取代基的影响，但仅在受体官能团中具有未取代的苯基或对甲基苯基氰基乙酰胺的探针中观察到近红外区域的强烈和 tau 选择性开启荧光。与母体化合物相比，新鉴定的探针对 Aβ 原纤维的 tau 选择性提高了 1.5 ～ 4.1 倍，荧光强度提高了 3.5 ～ 4.7 倍。