AbstractA catalytic cleavage strategy was developed for the fluorometric determination of Hg(II). The method is based on the use of a Mg(II)-dependent split DNAzyme. Fluorophore labeled hairpins were conjugated to gold nanoparticles (AuNPs) upon which fluorescence is quenched. Thymine-Hg(II)-thymine (T-Hg(II)-T) interaction causes the two DNA sequences to form an entire enzyme-strand DNA (E-DNA). The E-DNA bind to the hairpins on the AuNPs to form a Mg(II)-dependent DNAzyme structure. The circular cleavage of hairpins results in a signal amplification and in the recovery of fluorescence. The assay has a limit of detection (LOD) as low as 80 pM of Hg(II). This LOD is comparable to those obtained with other amplification strategies. The method was successfully applied to the determination of Hg(II) in Chinese herbs (Atractylodes macrocephala Koidz). Graphical abstractSchematic of a catalytic cleavage strategy based on Mg(II)-dependent split DNAzyme for fluorometric determination of Hg(II).

中文翻译：

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基于使用依赖于镁（II）的分裂脱氧核糖核酸酶和与金纳米粒子缀合的发夹，用于荧光测定 Hg（II）的催化裂解策略

摘要 开发了一种用于荧光法测定 Hg(II) 的催化裂解策略。该方法基于使用依赖于镁 (II) 的分裂 DNAzyme。荧光团标记的发夹与金纳米粒子 (AuNPs) 结合，荧光被淬灭。胸腺嘧啶-汞 (II)-胸腺嘧啶 (T-Hg(II)-T) 相互作用导致两个 DNA 序列形成完整的酶链 DNA (E-DNA)。E-DNA 与 AuNPs 上的发夹结合，形成依赖于 Mg(II) 的 DNAzyme 结构。发夹的圆形切割导致信号放大和荧光的恢复。该测定的检测限 (LOD) 低至 80 pM 的 Hg(II)。该 LOD 与使用其他扩增策略获得的 LOD 相当。该方法已成功应用于中草药（白术）中Hg(II)的测定。