One-step synthesis of poly(3,4-ethylenedioxythiophene)–Au composites and their application for the detection of nitrite

A simple one-step method was developed for the synthesis of poly(3,4-ethylenedioxythiophene)–Au nanoparticles (PEDOT–AuNPs) composite film by using a co-electrodeposition technique. The composites were further characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and UV–vis spectroscopy, which indicated that the uniform distribution of AuNPs was found within the conducting polymer films. Electrocatalytic properties of the composites toward the nitrite oxidation have been investigated by cyclic voltammetry and chronoamperometry. It was found that such PEDOT–AuNPs composites modified electrode showed a very high electrochemical activity for electrocatalytic oxidation of nitrite, which was utilized as the basis of the fabrication of a nonenzymatic sensor for electrochemical detection of nitrite. The sensor can be applied to the quantification of nitrite with a linear range covering from 3 to 300 μM and a low detection limit of 0.1 μM. Furthermore, the experiment results also showed that the sensor exhibited good reproducibility and long-term stability, as well as high selectivity.