Nitrite electrochemical sensor based on graphene quantum dots modified electrode

Material of grapheme quantum dots was dropped on the surface of glassy carbon electrode to form its film, and nitrite (NO₂^-) electrochemical sensor was prepared. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) were utilized to characterize grapheme quantum dots (GQDs). Meanwhile, electrochemical behavior of nitrite was researched by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and current-time curve (I-T) on the surface of modified electrode. The experimental results show that electrochemical sensor exhibits a good electrocatalysis to NO₂^- and possesses a broad linear range in 1~29 μmol/L with detection limit of 3.33×10-7 mol/L (S/N=3). The electrochemical sensor shows the characteristics of wide detection range, low detection limit and good stability.