The electrochemiluminescence (ECL) properties of polycyclic aromatic hydrocarbons (PAHs) are excellent on account of the high photoluminescence quantum yield. However, the poor solubility and radical instability of PAHs in the aqueous solution severely restricted further biological application. Here 9,10-diphenylanthracene (DPA) nanoblocks (NBs) with good dispersibility and stability in aqueous solution were prepared according to morphology-controlled technology employing water-soluble polymers as a protectant. Furthermore, an ECL “off–on” switch biosensor was developed based on a novel ECL ternary system with DPA NBs as luminophore, dissolved O₂ as coreactant, and Pt–Ag alloy nanoflowers as the coreaction accelerator, which achieved a high-intense initial ECL signal. Subsequently, the Fc-DNA as ECL signal quencher was assembled on the electrode surface to quench the initial ECL signal for a “signal-off” state. Meanwhile, DNA swing arm was modified on the electrode surface for one-step DNA walker amplification. Interestingly, in the presence of miRNA-141 and T7 Exo, the one-step DNA walker amplification was executed to recover a strong ECL signal as a “signal-on” state by the digestion of Fc-DNA. Thus the developed ECL “off–on” switch biosensor possesses a detection limit down to 29.5 aM for ultrasensitive detection of miRNA-141, which is expected to be applicable to the detection of miRNA in clinic tumor cells.

中文翻译：

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形态学控制的9,10-二苯基蒽纳米嵌段作为电化学发光发射体，用于一步式DNA Walker扩增的MicroRNA检测。

由于高的光致发光量子产率，多环芳族烃（PAH）的电致发光（ECL）性能非常好。但是，PAHs在水溶液中的不良溶解性和自由基不稳定性严重限制了进一步的生物学应用。在此，根据形态控制技术，使用水溶性聚合物作为保护剂，制备了在水溶液中具有良好分散性和稳定性的9,10-二苯基蒽（DPA）纳米嵌段（NBs）。此外，基于新型的ECL三元系统，以DPA NBs为发光体，溶解的O ₂为基础，开发了ECL“关闭-接通”开关生物传感器。Pt-Ag合金纳米花作为共反应促进剂，并实现了高强度的初始ECL信号。随后，将作为ECL信号淬灭剂的Fc-DNA组装在电极表面上，以淬灭初始ECL信号，使其处于“信号关闭”状态。同时，在电极表面修饰了DNA摆臂，以进行一步式DNA Walker扩增。有趣的是，在存在miRNA-141和T7 Exo的情况下，执行单步DNA Walker扩增以通过消化Fc-DNA将强ECL信号恢复为“ signal-on”状态。因此，已开发的ECL“关闭”开关生物传感器具有超低灵敏度的miRNA-141检测极限，检测极限低至29.5 aM，有望应用于临床肿瘤细胞中的miRNA检测。