基于对羧基苯硫酚自组膜免疫传感器的研究

Study on Direct Potentiometric Immunosensor Based on 4-Hydroxy Thiophenol SAMs

利用自组装技术将对羧基苯硫酚（4-MBA）固定在金片电极上，以1-乙基-3-（3-二甲氮基）碳二亚胺盐酸盐（EDC）和N-羧基硫代琥珀亚胺（NHS）作为活化剂，将羊抗-小鼠IgG以共价键形式固定在对羧基苯硫酚自组装单分子膜修饰的金片电极上，制备了一种免疫传感器。根据抗体与抗原之间特异反应前后引起的电极电位变化，对小鼠IgG进行定量测定。利用循环伏安法分别对裸金片电极、对羧基苯硫酚自组装膜、抗体膜、抗原膜进行了表征。结果表明，该免疫传感器灵敏度高、响应速度快、检测范围宽，其检测下限为0．1ng／mL，检测范围为0．6～30ng／mL，且该传感器的重现性较好。

An immobilization procedure of antibody on planar gold electrode is proposed. A pretreated planar gold electrode was first immersed in 4--Mereapto Benzoic Acid （4--MBA） solution for self assembly through the Au--S covalent bond. Then, antibody （sheep--anti--mouse IgG） was immobilized by means of covalent coupling with the activation of 1- ethyl- 3 -- [-3 -- （dimethylamino） propyl]earbodiimide hydroehloride .（EDC） and N-- hydroxysulfosueeinimide （NHS）. The sensitivity of the procedure is high with the deteetion limit of 0. 2 ng/mL and a linear range from 0. 2 to 30 ng/mL. Every im- mobilized step on planar Au electrode was characterized using eyelie voltammograms, and the result proved the immobilized steps were feasible.