College of Chemistry & Materials Science, Shaanxi Provincial Key Laboratory of Electroanalytical Chemistry, Northwest University, Xi'an, Shaanxi, 710069, China; Shaanxi Research Design Institute of Petroleum and Chemical Industry, Xi'an, Shaanxi, 710054, China.
College of Chemistry & Materials Science, Shaanxi Provincial Key Laboratory of Electroanalytical Chemistry, Northwest University, Xi'an, Shaanxi, 710069, China.
Talanta. 2021 Sep 1;232:122405. doi: 10.1016/j.talanta.2021.122405. Epub 2021 Apr 19.
The accurate measurement of heavy metal ions is essential for human health and environmental protection. Here, we report the design of a simple and convenient bimodal strategy for signal-on, label-free lead ion detection in environmental samples based on two-dimensional metal-organic framework (2D-MOF) nanosheets. 2D-MOFs have different affinities toward guanine-rich DNA (ssGDNA) and the G-quadruplex, allowing these structures to be distinguished. The nanosheets were also used as quenchers for fluorescent lead ion detection. Using lead ions to induce G-quadruplex formation from ssGDNA, a simple fluorescence resonance energy transfer (FRET) strategy was developed for lead ion detection; the detection limit was 3.3 nM. Based on changes in the GDNA configuration, the FRET system was converted into an electrochemical sensor for lead ion assays using an electrode modified with the 2D-MOF nanosheets. Electrochemical impedance spectroscopy showed a high sensitivity and a low limit of detection (i.e., 8.7 pM) of the electrode. The adaptability of the bimodal mechanism was verified through the successful detection of lead ions in tap water and fertilizer samples, and the method accuracy was demonstrated through inductively coupled plasma analysis. The developed bimodal device is cost-effective, highly sensitive, and allows for convenient operation, thereby rendering it a promising and reliable system for the detection of lead ions in environmental samples.
重金属离子的精确测量对人类健康和环境保护至关重要。在这里，我们报告了一种基于二维金属有机骨架（2D-MOF）纳米片的简单方便的双模态信号开启、无标记铅离子检测策略的设计。2D-MOF 对富含鸟嘌呤的 DNA（ssGDNA）和 G-四链体具有不同的亲和力，允许区分这些结构。纳米片还可用作荧光铅离子检测的猝灭剂。利用铅离子诱导 ssGDNA 形成 G-四链体，开发了一种用于铅离子检测的简单荧光共振能量转移（FRET）策略；检测限为 3.3 nM。基于 GDNA 构象的变化，该 FRET 系统被转换为使用修饰有 2D-MOF 纳米片的电极进行的用于铅离子分析的电化学传感器。电化学阻抗谱显示出电极的高灵敏度和低检测限（即 8.7 pM）。通过成功检测自来水中和肥料样品中的铅离子验证了双模态机制的适应性，并通过电感耦合等离子体分析证明了该方法的准确性。所开发的双模态装置具有成本效益、高灵敏度和方便的操作，因此是一种有前途且可靠的环境样品中铅离子检测系统。
