Abstract An electrochemical Hg(II) ion sensor has been developed by using a miniaturized carbon paste screen-printed electrode (CSPE) modified with reduced graphene oxide (rGO) sheets and tris-thiourea (TTU) chelating ligand compound, i.e. N,N′,N″-((nitrilotris(ethane-2,1diyl))tris(azanediyl))tris(carbonothioyl))tribenz amide. In view of the strong cation-exchange characteristic and adsorption of aromatic TTU tridentate ligand on the graphene nanomaterial surface by non-covalent π–π stacking interaction, the differential pulse voltammetry (DPV) peak current response of the voltammetric sensor was linearly dependent on a broad Hg(II) ion concentration detection range from 0.1–00.0 mg L−1 with a limit of detection (LOD) estimated at 0.02 mg L−1 after accumulation for 10 min. The chemically modified miniaturized SPE showed high stability throughout the course of the sensor lifetime study for the detection of inorganic Hg(II) ion with a relative standard deviation (RSD) of the sensor response obtained at 1.2%. The electrochemical sensor is reusable up to three consecutive Hg(II) ion assays by using 0.05 M acetate buffer (pH 8) as the sensor regeneration solution with a reversibility RSD value of 3.9%. The voltammetric sensor based on TTU derivative element and rGO nanosheets revealed satisfactory selectivity for Hg(II) ion over a large number of potential interfering ions, e.g. Ca(II), Co(II), Cu(II), Fe(II), Ni(II), Na(I) and Zn(II), and demonstrated reliable quantitative results as compared to the results obtained with inductively coupled plasma-mass spectrometer (ICP-MS) standard method for Hg(II) ion detection in river water samples.

中文翻译：

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基于三硫脲有机螯合配体接枝石墨烯纳米材料的可再生丝网印刷伏安Hg(II)离子传感器

摘要 利用还原氧化石墨烯 (rGO) 片和三硫脲 (TTU) 螯合配体化合物，即 N,N' 修饰的微型碳糊丝网印刷电极 (CSPE)，开发了一种电化学 Hg(II) 离子传感器。 ,N”-((次氮基三(乙烷-2,1二基))三(氮杂二基))三(硫代碳酰))三苯甲酰胺。鉴于芳族 TTU 三齿配体通过非共价 π-π 堆积相互作用在石墨烯纳米材料表面的强阳离子交换特性和吸附，伏安传感器的差分脉冲伏安 (DPV) 峰值电流响应线性依赖于宽泛的 Hg(II) 离子浓度检测范围为 0.1–00.0 mg L-1，累积 10 分钟后检测限 (LOD) 估计为 0.02 mg L-1。经化学修饰的小型化 SPE 在整个传感器寿命研究过程中表现出高稳定性，用于检测无机 Hg(II) 离子，传感器响应的相对标准偏差 (RSD) 为 1.2%。通过使用 0.05 M 醋酸盐缓冲液 (pH 8) 作为具有 3.9% 可逆性 RSD 值的传感器再生溶液，电化学传感器最多可重复使用三个连续的 Hg(II) 离子测定。基于 TTU 衍生元素和 rGO 纳米片的伏安传感器显示出对 Hg(II) 离子对大量潜在干扰离子的令人满意的选择性，例如 Ca(II)、Co(II)、Cu(II)、Fe(II)、 Ni(II)、Na(I)和Zn(II)，