“…In particular, gold was found to be the superior substrate as a working electrode for arsenic determination [20,29,30], because it provides a more sensitive response toward arsenic oxidation than other electrode materials and has a higher hydrogen overvoltage than platinum [31,32]. Problems occurring with solid electrodes include the dependence of their response on pre-treatment and the formation of oxide films, which limits sensitivity and reproducibility and, as a consequence, their use for routine applications [23,33].…”