Gel-Integrated mercury-plated microelectrode arrays for trace metal detection

The detection of trace metals is of great significance for understanding and utilizing ocean resources. However, in-situ detection of trace metals with high detection accuracy remains an important problem because of the complexity of the marine environment. In this paper, we have successfully fabricated gel-integrated mercury-plated microelectrode array sensors and realized the detection of trace metals in standard metal solutions by anodic stripping voltammetry (ASV). We have coated 1.5% agarose gel film on the microelectrode array, which can prevent electrodes from being polluted and not affect the diffusion of metal ions. For the analysis of trace metals, mercury is deposited on the iridium-based microelectrode array. Cyclic voltammetry shows that mercury plating effectively expands the negative application range of working electrodes and can be used for simultaneous detection of Zn, Cd and Pb. The detection limits of Zn, Cd and Pb were 0.63, 0.60 and 0.59 μg/mL in standard metal solution at the deposition time of 2000 s. In summary, quantitative detection of three metal ions in standard metal solution is realized, which embodies the advantages of anodic stripping voltammetry in seawater metal detection.