银掺杂聚L-天冬氨酸修饰电极的制备及对肾上腺素的测定

Preparation of Silver Doped Poly(L-Aspartic Acid) Modified Electrode and Determination of Epinephrine

利用循环伏安法,研究了银和L-天冬氨酸在玻碳电极表面电化学聚合的条件,制备了银掺杂聚L-天冬氨酸修饰电极。研究了肾上腺素在修饰电极上的电化学行为,建立了循环伏安法测定肾上腺素的新方法。在pH=3.5的磷酸盐缓冲溶液中,扫描速率为50mV/s时,肾上腺素在修饰电极上产生一对明显的氧化还原峰,峰电位分别为Epa=0.447V,Epc=0.387V。用循环伏安法测定时,氧化峰电流与肾上腺素浓度分别在8.00×10-8～1.00×10-5mol/L和1.00×10-5～1.00×10-4mol/L范围内呈良好的线性关系,检出限为8.0×10-9mol/L。

A silver doped poly （L-aspartic acid ） modified electrode （Ag-PLA/GCE） was prepared by electrochemical immobilization of silver and L-aspartic acid on a glassy carbon electrode surface. The polymerization conditions and the electrochemical behavior of epinephrine were studied. A novel cyclic vohammetric method was proposed for the determination of epinephrine. In a pH = 3.5 phosphate buffer solution, a pair of redox peaks were observed at peak potential Epa = 0. 447 V and Epc = 0. 387 V （vs. Ag/AgC1） at a scan rate of 50 mV/s. By cyclic vohammetry, the oxidation peak current of epinephrine was proportional to the concentration in a range of 8.00 × 10^-8 - 1.00 × 10^-5 mol/L and that of 1.00 × 10^-5 1.00 × 10^-4 mol/L. The detection limit was 8.0 × 10^ -9 mol/L.