This work provides a facile electrochemical method for simultaneous detection of Cd²⁺, Pb²⁺, and Cu²⁺, on the base of one-pot synthesis of triethanolamine (TEOA)-functionalized gold nanoparticle (AuNP)-metal–organic framework-graphene oxide nanocomposites (TEOA@AuNPs-GO-UiO-66-NH₂). In this method, TEOA not only can act as a base for the deprotonation of 2-aminoterephthalic acid, leading to in situ synthesizing the UiO-66-NH₂ on the GO nanosheets by a one-step hydrothermal method, but also can be used as a reductant reacted with HAuCl₄ to form AuNPs, improving the conductivity of the composite by accelerating the electron transfer. Moreover, this composite can serve as an enrichment medium phase of heavy metal ions because of the interaction between metal cations and hydrophilic groups of TEOA, UiO-66-NH₂, or GO, which have the synergic effect of enhancing the electrochemical signals. The morphology and structure information of TEOA@AuNPs-GO-UiO-66-NH₂ composite were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), and Fourier transform infrared spectrometer (FT-IR). Under the optimal conditions, the TEOA@AuNPs-GO-UiO-66-NH₂-modified electrode was applied for individual and simultaneous electrochemical detection for the Cd²⁺, Pb²⁺, and Cu²⁺ in an acetic acid buffer solution with satisfactory linear range and significantly low limits of detection. This electrochemical sensor was successfully utilized for simultaneous detection of Cd²⁺, Pb²⁺, and Cu²⁺ in river water with great selectivity and accuracy, displaying great potential application in food safety and environmental monitoring.

Graphical abstract

中文翻译：

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轻松一锅合成三乙醇胺功能化 AuNPs-GO-UiO-66-NH2 纳米复合材料，用于同时电化学检测 Cd(II)、Pb(II) 和 Cu(II)

本工作以三乙醇胺(TEOA)-功能化金纳米粒子(AuNP)-金属-有机骨架-一锅法合成为基础，提供了一种同时检测Cd ²⁺、Pb ²⁺和Cu ²⁺的简便电化学方法。氧化石墨烯纳米复合材料（TEOA@AuNPs-GO-UiO-66-NH ₂）。在该方法中，TEOA不仅可以作为2-氨基对苯二甲酸去质子化的碱，通过一步水热法在GO纳米片上原位合成UiO-66-NH ₂ ，而且还可以使用作为还原剂与HAuCl ₄反应形成AuNPs，通过加速电子转移来提高复合材料的电导率。此外，由于金属阳离子与TEOA、UiO-66-NH ₂或GO的亲水基团之间的相互作用，该复合物可以作为重金属离子的富集介质相，具有增强电化学信号的协同作用。通过扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线衍射(XRD)和傅里叶变换红外光谱仪对TEOA@AuNPs-GO-UiO-66-NH ₂复合材料的形貌和结构信息进行了表征。傅立叶变换红外）。在最佳条件下，采用TEOA@AuNPs-GO-UiO-66-NH ₂修饰电极对醋酸缓冲溶液中的Cd ²⁺、Pb ²⁺和Cu ²⁺进行单独、同时电化学检测。令人满意的线性范围和极低的检测限。该电化学传感器成功用于同时检测河水中的Cd ²⁺、Pb ²⁺和Cu ^{2+ ，具有良好的选择性和准确性，在食品安全和环境监测方面显示出巨大的应用潜力。}

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