银、L-半胱氨酸修饰电极同时测定多巴胺和抗坏血酸  

Preparation of silver and L-cysteine layered modified electrode and simultaneous determination of dopamine and ascorbic acid

作　　者：汤优霞 孙登明[1] 

机构地区：[1]淮北师范大学化学与材料科学学院,安徽淮北235000

出　　处：《化学传感器》2014年第4期39-43,共5页Chemical Sensors

基　　金：安徽省高校省级自然科学研究重点项目基金(No.KJ2011A255)

摘　　要：采用电聚合的方法将银、L-半胱氨酸先后修饰到电极表面，制备了银、L-半胱氨酸修饰电极fPLC／Ag／GCE）。研究了多巴胺和抗坏血酸在该修饰电极上的电化学行为，构建的电极可实现对多巴胺和抗坏血酸的同时检测。实验表明：在扫速为120mV／s，pH=3．0的磷酸盐缓冲溶液（PBS）中，多巴胺产生一对氧化还原峰，其氧化峰和还原峰的电位分别为0．447V和0．409V；而抗坏血酸只产生一个明显的氧化峰，其峰电位为0．238V。多巴胺和抗坏血酸的AEpa=0．209V，不需要分离便可对两者进行同时检测。在最佳条件下，测定多巴胺和抗坏血酸的线性范围分别为1．00×10-6～2．50×10-4mol/L和7．50×10-6--1．00×10-3mol／L．检出限分别为5．0×10-7mol／L和2．5×10-6mol／L。该方法可用于多巴胺和抗坏血酸的同时测定。An electrochemical biosensor has been fabricated based on silver and L-cysteine layered modified electrode for simultaneous determination of dopamine （DA） and ascorbic acid （AA）. The electrochemical behavior of DA and AA was studied by cyclic voltammetric method. The results indicated that a redox peaks of dopamine and an oxide peak of ascorbic acid were severally observed in Epa = 0.447 V ,Epc = 0.409 V and Epa = 0.238 V, in pH=3.0 phosphate buffer solution with the scan rate of 120 mV/s. The oxide potential difference （AEpa） of DA and AA was 0.209 V. The proposed biosensor exhibited the linear range 1.00× 10-4 ~ 2.50× 10-4 moFL and 7.50× 10-6 ~ 1.00× 10-3 mol/L with the detection limits 5.0×10-7 mol/L and 2.5×10-6 mol/L for simultaneous determination of AA and DA, respectively. The method has been applied to the determination of AA and DA in mixed tablets with satisfactory results.

关 键 词：AG L-半胱氨酸 多巴胺 抗坏血酸 循环伏安法 

分 类 号：R446.1[医药卫生—诊断学] O657.1[医药卫生—临床医学]