聚对氨基苯磺酸/石墨烯复合修饰电极对尿酸的选择性灵敏测定

摘要

采用电聚合方法在石墨烯纳米片(GN)的表面聚合一层聚对氨基苯磺酸( PABSA),制备了聚对氨基苯磺酸/石墨烯复合修饰玻碳电极(PABSA/GN/GCE).研究了尿酸(UA)和抗坏血酸(AA)在该修饰电极上的电化学行为.与聚对氨基苯磺酸修饰电极(PABSA/GCE)及石墨烯单层膜修饰电极(GN/GCE)相比,复合修饰电极PABSA/GN/GCE显著提高了对UA和AA的检测灵敏度和分离度.在0.1 mol/L磷酸盐缓冲溶液(pH7.0)中,UA和AA的峰电位差达344 mV,表明PABSA/GN/GCE能实现对UA的选择性测定.UA的峰电流与其浓度呈良好的线性关系,线性范围为1.0×10-7～8.0×10-4 mol/L,检出限为4.5×10-8 mol/L.该复合修饰电极用于尿样中尿酸的测定,结果满意.%A PABSA/GN/GCE composite-modified electrode was fabricated by using a graphene nanosheets(GN) modified glassy carbon electrode ( GCE) electropolymerized with p-aminobenzene sulfonic acid( PABSA). The electrochemical behaviors of uric acid( UA) and ascorbic acid( AA) on the nanocomposites-modified electrode were investigated. Compared with PABSA/GCE and GN/GCE, the PABSA/GN/GCE improved the resolution and the sensitivity for the determination of UA in the presence of AA. In 0. 1 mol/L phosphate buffer solution (pH 7. 0), a peak to peak separation of 344 mV was observed, which enabled the selective determination of UA. The peak currents obtained from DPV were linearly related to concentrations of UA in the range of 1. 0×10-7 - 8. 0×10 -4 mol/L. The detection limit was 4. 5×10-8 mol/L. The nanocomposites-modified electrode was adopted for the detection of UA in the human urine with satisfactory result.