银/聚对氨基苯磺酸/石墨烯复合膜修饰电极对双酚A的测定

Determination of bisphenol A on a silver/poly sulfanilic acid/graphene composite membrane modified electrode

以壳聚糖作为石墨烯分散剂，将壳聚糖分散的石墨烯滴涂于玻碳电极表面，晾干后通过循环伏安法共沉积银离子和对氨基苯磺酸单体制备了银／聚对氨基苯磺酸／石墨烯复合膜修饰电极。实验研究了环境激素双酚A在该修饰电极上的电化学行为，优化了测定双酚A的实验条件。结果表明，该修饰电板对双酚A有良好的电催化作用，在pH6．0的磷酸盐缓冲溶液中，双酚A在0．643V处有1个灵敏的氧化峰，峰电流与双酚A浓度在2×10^-5-5×10^-4mol／L范围内呈良好的线性关系。线性方程为：I（μA）=0．2793＋4790．3c（μmol／L），R^2=0．9942，检出限为2×10^-7mol／L（S／N=3），加标回收率在97．3％-107．4％之间，结果满意。据此建立了用石墨烯-L-氨基酸复合膜修饰电极测定食品包装材料中双酚A的快速分析方法。该修饰电极具有良好的选择性和灵敏度。

Chitosan was used as a dispersant graphene. The dispersed graphene with chitosan was cast on a glassy carbon electrode to fabricate a graphene modified glassy carbon electrode. After the graphene modified electrode was dried in the air, the silver ions and p-aminobenzenesulfonic acid （PABSA） were copolymerized on the surface of the graphene modified electrode with cyclic vohammetry to form a silver/paminobenzenesulfonic acid （PABSA） composite membrane. The electrochemical behavior of bisphenol A, an environmental hormone, on the modified electrode was studied by cyclic voltammetry. The conditions for the determination of bisphenol A were optimized. The results showed that the modified electrode had good electrocatalytic activity for the oxidation of bisphenol A. In the phosphate buffer solution of pH = 6.0, bisphenol A had a sensitive oxidation peak at 0. 643 V. The peak current of bisphenol A was linear with its concentration in the range of 2 ×10^ -5 - 5 × 10^ -4 mol/L. The linear regression equation was I（μA）=0.2793＋4790.3c（μmol/L）,R^2=0.9942 with R^2 = 0. 9942, and the detection limit was 2 × 10^-7mol/L. Based on this, a sensitive method for the determination of bisphenol A in food packaging materials was developed. The recoveries were in the range of 97.3% - 107.4%. The proposed method has high sensitivity and selectivity.