Electrochemical sensor for detection of p-nitrophenol based on nanoporous gold

Nanoporous gold (NPG) with uniform pore sizes and ligaments was prepared by a simple dealloying method. The as-prepared NPG samples were used as the working electrodes to investigate the redox behavior of p-nitrophenol (p-NP) by cyclic voltammetry (CV). Quite different from the voltammetric behavior of polycrystalline gold electrode, the CV profiles of NPG display a pair of nearly symmetric redox waves which are ascribed to the reaction of 4-(hydroxyamino)phenol/4-nitrosophenol couple. It is interesting that this pair of redox waves are hardly affected by the isomers of p-NP; and moreover, their peak areas are linear with the concentration of p-NP in the range from 0.25 to 10 mg dm−3. Because of high sensitivity and good selectivity, NPG is expected to act as a promising electrochemical sensor material for detecting trace p-NP in wastewaters.