L-半胱氨酸修饰金电极电化学发光法测定罗红霉素

Determination of Roxithromycin Based on L-Cysteine Modified Gold Electrode by Electrochemiluminescence

在裸金电极上制备了L-半胱氨酸自组装膜修饰电极(L-Cys-Au/SAM/CME)。考察了联吡啶钌和罗红霉素在此修饰电极上的电化学及其发光行为。结果表明,此修饰电极表现出了很好的电化学活性和电化学发光(ECL)响应。基于罗红霉素的存在可增大了联吡啶钌的发光强度,建立了测定罗红霉素片的电化学发光分析方法。在最佳实验条件下,罗红霉素浓度在1.0×10-7～1.0×10-4mol/L范围内与其相对发光强度呈线性关系,其线性回归方程为I=2×107C+384.02,r=0.9977;检出限(S/N=3)为1.0×10-7mol/L。连续测定1.8×10-5mol/L罗红霉素10次,发光强度的RSD为1.93%,表明此修饰电极具有较好的重现性,并将本方法用于罗红霉素片剂的检测。

L-cysteine self-assembled monolayer modified electrode（L-Cys/SAM-Au/CME） was fabricated on the surface of bare gold wire.The electrochemical and ECL characteristics of Ru（bpy）2＋3 and roxithromycin at the modified electrode were studied,and the modified electrode exhibits good electrochemical activity and ECL response.Based on the enhancement of the intensity of Ru（bpy）2＋3 in the presence of roxithromycin,ECL method was established for the determination of roxithromycin on the modified electrode（L-Cys/SAM-Au/CME）.Under the optional conditions,the ECL detection limit（S/N=3） for roxithromycin was 1.0×10-7 mol/L with a linear range from 1.0×10-7 mol/L to 1.0×10-4 mol/L（r=0.9969）.The RSD for 10 times determination of 1.8×10-5 mol/L roxithromycin was 1.9%.The modified electrode shows good recurrence.The method was applied to the determination of roxithromycin tablet with satisfactory results.