基于对氨基苯磺酸功能化石墨烯/Nafion复合膜修饰电极的咖啡因电化学传感器

Caffeine biosensor based on sulfanilic acid functionalized graphene sheets/Nafion composite film modified electrode

以对氨基苯磺酸功能化石墨烯（AS-GS）和0.1％ Nafion的甲醇溶液制备了一种新型的复合膜修饰电极．采用扫描电镜（SEM）对修饰电极进行了表征，并利用循环伏安法（CV）和微分脉冲伏安法（DPV）研究了咖啡因（CAF）在修饰电极上的电化学行为．在最优条件下，修饰电极对咖啡因的氧化有良好的电催化活性，氧化峰电流与咖啡因浓度在1～500μmol·L^ -1范围内呈良好的线性关系，检测限为5.31＆#215;10-7 mol·L^ -1（S/N＝3）．此外， AS-GS/Nafion复合膜修饰电极具有较高的灵敏性，较好的稳定性和重现性，可用于可乐和功能性饮料中咖啡因含量的快速检测．

The sulfanilic acid functionalized graphene sheets （AS-GS ） and methanol solution of 0.1%nafion are used to fabricate a new type of composite film modified electrode . T he modified electrode is characterized by scanning electron microscope （SEM ） . The electrochemical behaviors and kinetic properties of caffeine on the modified electrode are investigated by cyclic voltammetry （CV ） and the differential pulse voltammetry（DPV） . The modified electrode displays excellent electrochemical catalytic activities toward the oxidation of caffeine under the optimum condition . The peak current is linearly dependent on the CAF concentrations in the range of 1~500 μmol·L^ -1 with the detection limit （S/N=3） of 5.31 ＆#215; 10-7 mol·L^ -1 . In addition , the composition film of AS-GS/Nafion modified electrode show s high sensitivity ,favorable stability and reproducibility .Moreover ,AS-GS/Nafion modified electrode has been applied to the quick determination of CAF in the cola and functional beverage .