We report here on the development and application of a submersible, compact, low power consumption, integrated multichannel trace metal sensing probe (TracMetal). This probe is unique in that it allows high-resolution, simultaneous in-situ measurements of the potentially bioavailable (so-called dynamic) fraction of Hg(II), As(III), Cd(II), Pb(II), Cu(II), Zn(II). The TracMetal incorporates nanostructured Au-plated and Hg-plated gel-integrated microelectrode arrays. In addition to be selective to the fraction of metal potentially bioavailable, they offer protection against fouling and ill-controlled convective interferences. Sensitivities in the low pM for Hg(II) and sub-nM for the other target trace metals is achieved with precision ≤ 12%. The TracMetal is capable of autonomous operation during deployment, with routines for repetitive measurements (1-2 h⁻¹), data storage and management, data computer visualization, and wireless data transfer. The system was successfully applied in the Arcachon Bay, to study the temporal variation of the dynamic fraction of the trace metals targeted. The in situ autonomous TracMetal measurements were combined with in situ measurements of the master bio-physicochemical parameters and sample collection for complementary measurements of the dissolved metal concentrations, organic matter concentrations and proxy for biological activities. The integration of all data revealed that various biotic and abiotic processes control the temporal variation of the dynamic fractions of the target metals (Me_dyn). The difference in the percentage of the dynamic forms of the metals studied and the short-term processes influencing their variation highlight the TracMetal potentiality as metal bioavailability-assessment sentinel to achieve comprehensive environmental monitoring of dynamic aquatic systems.

我们在此报告了一种潜水式、紧凑型、低功耗、集成多通道痕量金属传感探头 (TracMetal) 的开发和应用。该探头的独特之处在于它允许高分辨率、同步原位测量 Hg(II)、As(III)、Cd(II)、Pb(II)、Cu(II)、Zn(II) 的潜在生物利用度（所谓的动态）分数。TracMetal 包含纳米结构的镀金和镀汞凝胶集成微电极阵列。除了对潜在生物可利用的金属部分具有选择性外，它们还提供防止结垢和控制不良的对流干扰的保护。对 Hg(II) 的低 pM 灵敏度和对其他目标痕量金属的亚 nM 灵敏度达到了 ≤ 12% 的精度。TracMetal 能够在部署期间自主操作，具有重复测量的例程（1-2 h ^-1)、数据存储和管理、数据计算机可视化和无线数据传输。该系统已成功应用于阿卡雄湾，以研究目标微量金属动态分数的时间变化。该原位自主TracMetal测量使用合并在原位主生物物理化学参数和用于溶解的金属浓度的互补测量，有机物的浓度和代理用于生物活性样品收集的测量结果。所有数据的整合表明，各种生物和非生物过程控制着目标金属动态部分的时间变化（Me _dyn）。所研究金属的动态形式百分比的差异以及影响其变化的短期过程突出了 TracMetal 作为金属生物利用度评估哨兵实现动态水生系统综合环境监测的潜力。