Improved sensitivity and reproducibility in electrochemical detection of trace mercury (II) by bromide ionelectrochemical oxidation

Nanostructured gold electrodes have been widely used for electrochemical trace analysis of Hg2+ because Hg2+ has superior specificity for the formation of gold amalgam. However, it is still very challenging to achieve both high sensitivity and reproducibility, especially for real environmental water samples due to surface poisoning by organic residues. In this work, we developed two strategies for addressing these challenges. First, we added NaBr (with a final concentration of 0.01 M) to the analytes; this enhanced the sensitivity by two orders of magnitude and improved the reproducibility to be better than RSD