Abstract：
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 Hg2+ and Pb2+. 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-Hg2+-T mismatch structure and specific cleavage of the Pb2+-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 Hg2+ and Pb2+, respectively, with detection limits of 0.11 pM (Hg2+) and 0.093 pM (Pb2+). The aptasensor was also used for detecting Hg2+ and Pb2+ in water samples with good recoveries. Overall, this electrochemical aptasensor shows promising potential for sensitive and selective detection of heavy metals in environmental samples.
摘要：
环境中的重金属污染由于其对人类健康和环境的有害影响而成为全球关注的重要问题。在这项研究中,我们报道了一种同时检测Hg2和Pb2的电化学传感器。在金电极表面引入金纳米花/聚乙烯亚胺还原的氧化石墨烯(AuNFs/PEI-rGO)以提高传感性能。aptasensor基于T-Hg2-T错配结构的形成和Pb2依赖性DNA酶的特异性裂解，导致通过在探针DNA-1的3'末端标记的亚甲基蓝（MB）的ExoIII特异性消化和由信号标记催化的底物抗坏血酸（AA）的还原产生双重信号。用MB信号的降低和AA氧化峰的增加来表示Hg2+和Pb2+的含量，分别,检测限为0.11pM(Hg2+)和0.093pM(Pb2+)。该aptasensor还用于检测水样中的Hg2和Pb2，具有良好的回收率。总的来说,这种电化学aptasensor显示出有前途的潜力，用于敏感和选择性地检测环境样品中的重金属。
