Porous Copper-Modified Graphite Pencil Electrode for the Amperometric Detection of 4-Nitrophenol

To overcome the well-known carbon electrodes surface fouling of phenols, we report on a simple and rapid method for the preparation of a disposable porous Cu-modified graphite pencil electrode (Cu-GPE) for sensing 4-nitrophenol (4-NP). The bare- and Cu-modified graphite pencil electrodes were characterized by cyclic voltammetry and SEM. The two electrodes displayed distinct electrocatalytic activities in response to the electrochemical redox reaction of 4-NP. A difference of three orders of magnitude is obtained on the amperometric detection limits of 1.9μM on porous Cu-modified vs. 1.0mM on bare-graphite pencil electrode at 3σ. The Cu-GPEs are fabricated utilizing a simple single method, and at an extremely low cost with high stability, selectivity and sensitivity, offering a promising tool for sensing 4-NP.