A facile and efficient nitrite electrochemical sensor based on N, O co-doped porous graphene film

Abstract

Increasing food safety awareness in our daily life has called for the establishment of rapid toxic nitrite detection techniques. In this work, we reported on a facile, quick laser processing method for the preparation of N, O co-doped porous graphene, which was patterned using a computer-controlled system to directly engrave a commercial polyimide (PI) tape, and subsequently used as an electrode for electrochemical nitrite detection. The laser-induced graphene (LIG) was characterized using various physical methods, and the electrochemical performance of the LIG sensing electrode was investigated by cyclic voltammetry (CV), differential pulse voltammetry (DPV), and chronoamperometry (CA). The designed electrode exhibited outstanding sensing ability toward nitrite oxidation. The peak current of the DPV curve had a good linear relationship with analyte concentrations ranging from 5 to 450 μmol/L, and the limit of detection (LOD) was calculated to be 0.8 μmol/L (S/N = 3). None of the common cations and anions yielded a positive current response, demonstrating that the electrode showed superior selectivity for electrochemical nitrite recognition. Furthermore, we observed and elucidated the pH dependence of electrocatalytic activity, which was attributed to the synergy of the surface functional groups derived from N, O co -doped graphene. Owing to its fast response and anti-interference capacity, this new LIG electrode offers great potential as a nitrite electrochemical sensor for environmental applications.