【摘要】 研究了阿魏酸修饰电极的制备、性质及对 NADH的电催化作用 .该电极在 0 .1 mol/L磷酸缓冲溶液( p H =6.60 )中 ,于 -0 .1～ +0 .5 0 V ( vs. Ag/Ag Cl)电位范围内呈现一对氧化还原峰 ,其式量电位 E0 为+0 .1 88V( vs.Ag/Ag Cl) ,且 E0 随 p H增加而负向移动 .电子转移系数为 0 .496,表观电极反应速率常数( ks)为 6.6s-1.电极反应的电子数为 1且有 1个质子参与 .该修饰电极对 NADH氧化具有很好的催化作用 .在 NADH存在下 ,电极过程由扩散控制 ,扩散系数为 1 .76× 1 0 -6cm2 /s.NADH浓度在 0 .0 1～ 5 .0 mmol/L范围内与峰电流呈现良好的线性关系 .通过计时安培法测得催化速率常数为 6.82× 1 0 3 mol-1· L· s-1.更多还原

【Abstract】 The preparation of poly(ferulic acid) glassy carbon modified electrode and its electrochemical properties were studied. The modified electrode gives a quasi-reversible redox peaks in 0.1 mol/L phosphate buffer solution(pH=6.60) over the potential range from -0.1 to 0.5 V(vs. Ag/AgCl), in which the formal potential is 0.188 V(vs. Ag/AgCl). The formal potential shifts in a negative direction with the increasing of pH values. The electrode reaction contains one electron and one proton. The PFA modified electrode shows an electrocatalytic activity for the oxidation of NADH in 0.1 mol/L phosphate buffer solution. The apparent electron transfer rate constant(k s) and transfer coefficient for electron transfer between the electrode surface and immobilized PFA were calculated as 6.6 s -1 and 0.496, respectively, the diffusion coefficient of NADH was calculated as 1.76×10 -6 cm 2/s by using chronoamperometric results. The peak currents were proportional to the concentrations of NADH in the range of 0.01-5.0 mmol/L. Finally the heterogeneous rate constant for the oxidation of NADH on the PFA modified electrode surface was also determined and found to be about 6.82×10 3 mol -1·L·s -1.更多还原