Voltammetric Determination of Serine using L‐cysteine Modified Platinum Electrode and Brief Exploration from the Theoretical Perspective

Bingchun Xue; Yan Fu; Jing Li; Erbao Liu

Index: 10.1002/elan.201700682

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Abstract

A new method for the detection of serine was described using L‐cysteine chemically modified electrode, which was prepared by cyclic voltammetry. The factors, such as pH, scan rate, and soaking time for the experimental process were discussed. Under the optimal conditions, the linear range for serine concentration was 3×10−7∼8×10−5 mol L−1, the detection limit was 2.34×10−7 mol L−1 (S/N=3), and the relative standard deviation was 2.14 % (n=10) for 3×10−7 mol L−1 serine solution. The method was applied to the detection of serine in apple cider vinegar sample with a recovery of 97.5 %–101.9 %. To further discuss the change of the property of platinum surface on atomic level, theoretical calculations were carried out. The change of adsorption energy indicated that the possible interaction of Pt and cysteine was O−C−O bridge adsorption. The analysis about the density of states (DOS) of the system and pseudo band gap showed an increase in the Pt surface activity.