Au nanoparticle modified carbon paper electrode for an electrocatalytic oxidation nitrite sensor

In this article, the direct electrochemical behavior of nitrite at a Au nanoparticles (AuNPs)/carbon paper (CP) electrode made using a rapid electrochemical deposition method was investigated. The morphology of the AuNPs on the CP surface was characterized by scanning electron microscopy (SEM). The existence of the Au element was verified by energy dispersive spectroscopy (EDS). The crystal structure of the AuNPs was verified by X-ray diffraction (XRD). Cyclic voltammetry (CV) was applied to evaluate the electrochemical behavior of nitrite oxidation. Under the optimum conditions, the AuNPs/CP electrode exhibited a very strong response to nitrite; the oxidation peak current linearly increased with increasing nitrite in the ranges of 1 mu M to 30 mu M and 40 mu M to 100 mu M with correlation coefficients of 0.99883 and 0.99789, and a low detection limit of 0.093 mu M. The suggested sensor demonstrated high sensitivity, good reproducibility and good recovery.