抗坏血酸与牛血清白蛋白相互作用的光谱和电化学研究

Studies on the Interaction of Ascorbic Acid and Bovine Serum Albumin by Spectroscopic and Voltammetric Methods

用自制修饰电极通过循环伏安法和荧光法,分别研究牛血清白蛋白与抗坏血酸的相互作用.用循环伏安法和荧光法测得抗坏血酸与牛血清白蛋白的结合常数K分别为1.761×10~4L/mol和1.884×10~4L/mol,结合位点数均接近1.0.实验测得抗坏血酸对牛血清白蛋白是静态猝灭.抗坏血酸浓度与牛血清白蛋白荧光强度的降低在2.50×10^(-7)~3.50×10^(-4)mol/L范围内呈线性关系,检出限为1.0×10^(-7)mol/L.牛血清白蛋白浓度与抗坏血酸氧化峰电流的下降在2.50×10^(-8)~5.00×10^(-5)mol/L范围内呈线性关系,检出限为1.0×10^(-9)mol/L.此法用于样品中抗坏血酸和牛血清白蛋白的测定,结果满意.

The interaction between ascorbic acid（AA）and bovine serum albumin（BSA）was investigated us-ing the self- made modified electrode by cyclic voltammetry and fluorescence. The binding constants of1.761×10^4L/mol and 1.884×10^4L/mol can be calculated from the data obtained from fluorescence quenchingexperiments and cyclic voltammetry,respectively. And the number of the binding sites is nearly 1.0. The in-teraction of bovine serum albumin with AA was a single static quenching procedure. Within the limits,thefluorescence intensity changes BSA linearly with the concentrations of AA,the linear range is 2.50×10^（-7）～3.50×10^（-4）mol/L,and the detection limit is 1.0×10^（-7）_mol/L. Within the limits,the redox peak current of AAwas proportional to the the concentration of BSA,the linear range is 2.50×10^（-8）～5.00×10^（-5）mol/L,and the de-tection limit is 1.0×10^（-9）mol/L. It has been applied to the determination BSA and AA in the samples with sat-isfactory results.