Abstract A novel indirect electrochemical approach is reported to improve the sensitivity of Hg2+ quantification in environmental water samples. This strategy is based on the Hg2+ induced selective interaction of thymine mismatched pairs in a thymine-rich aptamer DNA to improve the specificity, while template-independent terminal deoxynucleotidyl transferase (TdT) extended the 3′-OH aptamer termini with repeated bases and increased the sensitivity. The introduction of the target Hg2+ blocked aptamer extension. Taking advantage of an electrochemical platform, this aptamer-TdT based amplification sensor enabled the specific quantification of Hg2+ ion over a wide linear range from 2 pM to 20 nM with a low limit of detection equal to 0.1 pM. The proposed strategy is promising for the detection of other metal ions.

中文翻译：

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通过锚定酶促延伸适体进行 Hg(II) 定量的电化学放大

摘要 据报道，一种新型间接电化学方法可提高环境水样中 Hg2+ 定量的灵敏度。该策略基于 Hg2+ 诱导富含胸腺嘧啶的适体 DNA 中胸腺嘧啶错配对的选择性相互作用以提高特异性，而不依赖模板的末端脱氧核苷酸转移酶 (TdT) 使用重复碱基扩展了 3'-OH 适体末端并增加了灵敏度。目标 Hg2+ 的引入阻止了适体延伸。利用电化学平台，这种基于适体-TdT 的放大传感器能够在 2 pM 至 20 nM 的宽线性范围内对 Hg2+ 离子进行特异性定量，检测下限等于 0.1 pM。所提出的策略有望用于检测其他金属离子。