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

4-aminophenol (4-AP) is a highly toxic environmental pollutant and medicine contaminant widely used in industries and our daily life. Therefore, to develop a reliable sensor for tracing the amount of 4-AP is of great importance to environmental and healthy protections. Herein, by fabricating Pd@CeO2 composite on nanoporous gold coated carbon fiber paper (NPG/CFP), the sensing property for 4-AP can be largely enhanced. Combining the significant catalytic activity elevation of Pd@CeO2 composite (derived from the strong interaction between Pd and CeO2) to the NPG and NPG/CFP hierarchical porous structure with high electrochemical active surface area, the electrode reaches excellent detecting performance in 4-AP. It manifests an extremely high sensitivity of 75.4 µA µM-1 and 56.5 µA µM-1 under the concentration range from 0.005 µM to 0.03 µM and 0.03 µM to 9 µM, respectively. The detection limit reaches as low as 4 nM under optimized condition (S/N = 3). Meanwhile, the electrode possesses long-term stability and presents great anti-interference ability. All these results demonstrate that the electrode should be a promising candidate of future monitoring sensors for 4-AP in water and pharmaceticals.