Fabrication of a Silver Nanoparticle/polydopamine Modified Glassy Carbon Electrode and Its Electrocatalytic Reduction for p-Nitrophenol

A glassy carbon electrode modified with silver particles under polydopamine film was prepared successfully by means of electropolymerization and pulsed electrodeposition. A detailed analysis of the scanning electron microscope images reveals that silver deposit, obtained under pulsed electrodeposition conditions, appears as homogeneously compact and the crystallites are well dispersed on the overoxidized polydopamine substrate than that observed on the unmodified glassy carbon surfaces. The resulting silver nanoparticle/polydopamine modified glassy carbon electrode(Ag/PDA/GC) was electrochemically characterized through the reduction of p-nitrophenol(pNP). The potential needed for the reduction of the compound on the Ag/PDA/GC electrode is significantly less negative than that observed on the unmodified glassy carbon electrode substrates. A linear relationship between pNP concentration and current response was obtained in the range of 4 x 10(-5)-3 x 10(-4) mol/L. The Ag/PDA/GC would be used in the practical application for detecting toxic nitrophenols.