以玻碳电极(GCE)为基底电极,采用1-乙基-(3-二甲基氨基丙基)碳酰二亚胺盐酸盐(EDC-HCI)和N-羟基琥珀酰亚胺(NHS)为偶联剂将半胱氨酸(Cys)与壳聚糖(Chi)交联,形成带有巯基和氨基官能团的功能化天然高分子生物膜。再利用Chi-Cys复合膜的活性基团将纳米金颗粒吸附到电极表面,最后利用形成的纳米金层吸附癌胚抗体(anti-CEA),制得癌胚抗原免疫传感器.实验结果表明,以铁氰化钾为氧化还原探针,该传感器对癌胚抗原(CEA)具有良好的电流响应。该传感器的线形范围为0.2~10.0ng/mL和10.0~80.0ng/mL,检出限(3σ)为0.08ng/mL。此外,采用循环伏安和交流阻抗技术对电极的制备过程进行了研究。该实验方法中电极制备简单,操作简便,有较高的灵敏度,实现了对CEA的分析测定。
Chitosan and cysteine are first crosslinked by EDC·HC1 and NHS, which form the functional biomembrane with thiol group and amino group. Next, nano gold is adsorbed to the electrode surface by the active groups. Finally, anti-CEA are adsorbed to prepare the carcinoembryonic antigen immunosensor. The experiment indicates that this sensor shows good electric current response to CEA by using potassium ferricyanide as the oxidation-reduction probe. The liner range of the sensor is from 0.2-10.0 ng/mL to 10.0-80. 0 ng/mL with a detection limit of 0.08 ng/mL. The results of voltammetry and electrochemical impendence spectroscopy show that the fabrication steps are simple and convenient and the immunosensor has relatively high sensitivity.