Tercier-Waeber Mary-Lou, Abdou Melina, Fighera Marianna, Kowal Justyna, Bakker Eric, van der Wal Peter
Department of Inorganic and Analytical Chemistry, University of Geneva, 1211 Geneva 4, Switzerland.
Ecole Polytechnique Fédérale de Lausanne (EPFL), 2002 Neuchâtel 2, Switzerland.
ACS Sens. 2021 Mar 26;6(3):925-937. doi: 10.1021/acssensors.0c02111. Epub 2021 Feb 18.
The development and field validation of newly designed nanostructured gold-plated gel-integrated microelectrode (Au-GIME) arrays applied to the direct square wave anodic stripping voltammetry (SWASV) quantification of the potentially bioavailable inorganic mercury (Hg(II)) species in the coastal area are presented. The Au-GIME consists of arrays of 100-500 interconnected iridium (Ir)-based microdisks that are electroplated with renewable Au nanoparticles (AuNPs) or Au nanofilaments (AuNFs) and covered with an agarose gel. The gel protects the sensor surface from fouling and ensures that mass transport of analytes toward the sensor surface is by pure diffusion only and therefore independent of the ill-controlled convective conditions of the media. The responses of these sensors to direct SWASV measurements of inorganic Hg(II) at near-neutral pH were investigated first in synthetic media and then in UV-irradiated marine samples. The analytical responses were found to be correlated to the number of interconnected microelectrodes and the morphology of the nanostructured Au deposits and independent of the media composition for chloride concentration ≥0.2 M (salinity ≥ 13) and pH ranging from 7 to 8.5. The AuNF-GIMEs have detection and quantification limits at a low pM level, fulfilling the requirement of sentinel tools for real-time monitoring of the dynamic fraction of Hg(II) in coastal area. The AuNF-GIMEs were incorporated in an in-house advanced multichannel sensing probe for remote high-resolution trace metal monitoring. Field evaluation and validation were successfully performed as a part of a field study in Arcachon Bay (France), from which environmental data are presented. This work marks the first time that an autonomous electrochemical sensing probe successfully measures Hg(II) and its hourly temporal variation without chemical modification of the sample.
本文介绍了新设计的纳米结构镀金凝胶集成微电极（Au-GIME）阵列的开发及其现场验证，该阵列应用于直接方波阳极溶出伏安法（SWASV）对沿海地区潜在生物可利用的无机汞（Hg(II)）物种进行定量分析。Au-GIME由100 - 500个相互连接的铱（Ir）基微盘阵列组成，这些微盘电镀有可再生的金纳米颗粒（AuNPs）或金纳米丝（AuNFs），并覆盖有琼脂糖凝胶。该凝胶可保护传感器表面免受污染，并确保分析物仅通过纯扩散向传感器表面进行质量传输，因此与介质难以控制的对流条件无关。首先在合成介质中，然后在紫外线照射的海洋样品中，研究了这些传感器对近中性pH下无机Hg(II)的直接SWASV测量的响应。发现分析响应与相互连接的微电极数量和纳米结构金沉积物的形态相关，并且对于氯化物浓度≥0.2 M（盐度≥13）且pH范围为7至8.5的介质，与介质组成无关。AuNF-GIME在低皮摩尔水平具有检测和定量限，满足了实时监测沿海地区Hg(II)动态分数的哨兵工具的要求。AuNF-GIME被集成到一个内部先进的多通道传感探头中，用于远程高分辨率痕量金属监测。作为法国阿卡雄湾实地研究的一部分，成功进行了现场评估和验证，并展示了环境数据。这项工作标志着首次使用自主电化学传感探头成功测量Hg(II)及其每小时的时间变化，而无需对样品进行化学修饰。
