Nanoporous Gold Leaf for Amperometric Determination of Nitrite

Ultra-thin free-standing nanoporous gold leaf made by dealloying exhibits excellent electrocatalytic activities toward nitrite oxidation. The electrochemical responses of nitrite ions on this novel nano-electrode is found not dependent on pH over a wide range from 4.5 to 8.0, which is markedly different from that of gold oxidation, a process known to be highly pH-sensitive. Amperometric study shows a linear relationship for nitrite determination in a concentration range from 1 mu M to 1 mM. This nanostructured gold electrode displays good stability, repeatability and selectivity which suggests its potential for the development of new electrochemical sensors.