A novel dinuclear Schiff-base copper(II) complex modified electrode for ascorbic acid catalytic oxidation and determination

A new dinuclear copper salicylaldehyde-glycine Schiff-base complex [Cu2(Sal-Gly)2(H2O)2] was synthesized and structurally characterized. [Cu2(Sal-Gly)2(H2O)2] crystallized in the monoclinic system in the P21/c space group. The molecule is a dinuclear complex, formed by two [Cu(Sal-Gly)(H2O)] units. The electropolymerization properties of the copper complex on a glass carbon electrode were studied at different potential ranges. The electropolymerization occurred when the high scan potential reached 1.4 V. The modified electrode exhibited good electrocatalytic oxidation properties to ascorbic acid and showed a sensitivity of 22.9 nA μM−1 (r2 = 0.9998) and detection limit of 0.39 μM (S/N = 3) in the amperometric determination of ascorbic acid. The designed determination method can be used to analyze vitamin C tablets.