Electrochemical determination of nitrite at a bare glassy carbon electrode; why chemically modify electrodes?

The oxidation of nitrite was studied at a bare glassy carbon (GC) electrode in aqueous solution using cyclic voltammetry, square wave voltammetry and chronoamperometry. A mechanism for the electrode reaction is proposed. A limit of detection (LOD) of 4×10−7 M was obtained for amperometry and this is evaluated with reference to literature reports for NO2−NO2− detection; in particular, the possible merits of using chemically modified electrodes as compared to ‘bare’ unmodified electrodes are critically assessed.