Significant enhancement in the electrochemical determination of 4-aminophenol from nanoporous gold by decorating with a Pd@CeO2 composite film

Abstract

4-Aminophenol (4-AP) is a highly toxic environmental pollutant and contaminant of medicine, which is widely used in industries and daily life. Therefore, the development of a reliable sensor for determining the amount of 4-AP is of great importance for the protection of human and environmental health. Herein, by fabricating a Pd@CeO₂ composite on a nanoporous gold-coated carbon fiber paper (NPG/CFP), the sensing properties for 4-AP can be largely enhanced. Combining the significant increase in the catalytic activity of the Pd@CeO₂ composite (derived from the strong interactions between Pd and CeO₂) with the NPG and NPG/CFP hierarchical porous structure having a high electrochemically active surface area, the electrode achieved excellent detection of 4-AP. It manifested an extremely high sensitivity of 75.4 μA μM⁻¹ and 56.5 μA μM⁻¹ in the concentration range from 0.005 μM to 0.03 μM and 0.03 μM to 9 μM, respectively. The detection limit reached as low as 4 nM under optimized conditions (S/N = 3). The electrode also possesses long-term stability and presents great anti-interference ability. All these results demonstrate that the electrode is a promising candidate for future sensors for monitoring 4-AP in water and pharmaceuticals.