Heavy metal pollution in the environment has become a significant global concern due to its detrimental effects on human health and the environment. In this study, we report an electrochemical aptasensor for the simultaneous detection of Hg and Pb. Gold nanoflower/polyethyleneimine-reduced graphene oxide (AuNFs/PEI-rGO) was introduced on the surface of a gold electrode to improve sensing performance. The aptasensor is based on the formation of a T-Hg-T mismatch structure and specific cleavage of the Pb-dependent DNAzyme, resulting in a dual signal generated by the Exo III specific digestion of methylene blue (MB) labeled at the 3′ end of probe DNA-1 and the reduction of the substrate ascorbic acid (AA) catalyzed by the signal label. The decrease of MB signal and the increase of AA oxidation peak was used to indicate the content of Hg and Pb, respectively, with detection limits of 0.11 pM (Hg) and 0.093 pM (Pb). The aptasensor was also used for detecting Hg and Pb in water samples with good recoveries. Overall, this electrochemical aptasensor shows promising potential for sensitive and selective detection of heavy metals in environmental samples.

中文翻译：

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使用电化学适体传感器同时检测水样中的 Hg2+ 和 Pb2+，并通过核酸外切酶 III 和金属有机框架进行双信号放大


环境中的重金属污染因其对人类健康和环境的不利影响而成为全球关注的重大问题。在这项研究中，我们报道了一种用于同时检测汞和铅的电化学适体传感器。在金电极表面引入金纳米花/聚乙烯亚胺还原氧化石墨烯（AuNFs/PEI-rGO）以提高传感性能。该适体传感器基于 T-Hg-T 错配结构的形成和 Pb 依赖性 DNAzyme 的特异性切割，从而通过 Exo III 特异性消化 3' 端标记的亚甲基蓝 (MB) 产生双重信号探针 DNA-1 的合成和信号标记催化的底物抗坏血酸 (AA) 的还原。 MB信号的降低和AA氧化峰的增加分别用来指示Hg和Pb的含量，检测限为0.11 pM（Hg）和0.093 pM（Pb）。该适配体传感器还用于检测水样中的汞和铅，回收率良好。总体而言，这种电化学适体传感器在灵敏和选择性检测环境样品中的重金属方面显示出巨大的潜力。