卡维地洛的电化学测定及与牛血清白蛋白相互作用的研究

建立了测定卡维地洛(CAR)新的电化学方法.结合紫外、红外光谱分析,研究了CAR与牛血清白蛋白(BSA)的相互作用.实验发现,在pH4.0Britton-Robinson(B-R)缓冲溶液中,CAR在碳糊电极上产生3个不可逆的氧化峰.以0.92V处的氧化峰为研究对象,结果发现峰电流Ipa,1与CAR浓度在2.45×10-5～1.19×10-3mol/L范围呈良好的线性关系,CAR的检出限为5.6×10-6mol/L.当BSA加入CAR溶液后,CAR峰电流降低,氧化峰电流的降低值△Ipa,1与BSA的浓度在2.92×10-7～1.09×10-5mol/L范围内呈良好线性关系,BSA的检出限为4.1×10-8mol/L.电化学结果表明,CAR与BSA之间形成1∶1的结合物,结合常数为3.14×106L/mol.紫外光谱表明CAR的加入使BSA的吸收峰发生红移且有增色效应.红外光谱表明CAR与BSA分子中氨基酸残基的硫及氮原子形成键合作用.

Electrochemical determination of carvedilol and its interactions with bovine serum albumin

A novel electrochemical method for the determination of carvedilol(CAR) has been developed on a carbon paste electrode(CPE).The interactions between CAR and bovine serum albumin(BSA) were investigated by linear sweep voltammetry,differential pulse voltammetry,UV absorption and IR spectroscopies.Three irreversible oxidation peaks of CAR were observed at 0.92 V,1.18 V and 1.31 V in pH 4.0 Britton-Robinson(B-R) buffer solution,respectively.The oxidation peak current at 0.92 V was linear with the concentration of CAR in the range of 2.45×10-5 ～ 1.19×10-3 mol/L with a detection limit of 5.6×10-6 mol/L.The relative standard deviation(n=11) for 3.64×10-4 mol/L CAR was 4.8%.In the presence of BSA,the oxidation current of CAR decreased and the decreasing value was linear with the BSA concentration in the range of 2.92×10-7 ～1.09×10-5 mol/L,with a detection limit of 4.1×10-8 mol/L.The binding equilibrium constant and binding ratio were calculated as 3.14×106 L/mol and 1:1.UV absorption spectra showed that the redshift happened for the UV absorption peak of BSA and the maximum absorption value was increased.IR spectra showed that CAR could interact with sulfur-containing and nitrogen-containing groups in BSA molecule.