基于电聚合作用的脂质体免疫传感器检测水体中毒莠定的实验研究

利用脂质体包埋亚铁氰化钾,通过戊二醛交联毒莠定兔抗制成免疫脂质体,开发快速检测水中毒莠定的夹心型免疫传感器.在修饰电极的成分等方面优化传感器的工作参数,确定了Nation、多壁碳纳米管(multiwalled carbon nanotubes, MWCNTs)和毒莠定兔抗浓度的最优值分别为0.5%、10mg·mL-1、50μg·mL-1.免疫传感器的制作及测定过程如下:采用循环伏安法促使3,4-乙烯二氧噻吩(3,4-ethylendioxythiophene, EDOT)发生电聚合作用,将毒莠定兔抗直接固定到被修饰的玻碳电极上,电极再依次与待测水样和毒莠定兔抗修饰的免疫脂质体培育一定时间,最后利用TfitonX-100溶解与抗原结合的免疫脂质体,采用方波伏安法检测还原电流以反映毒莠定浓度,整个检测过程可以在70rain内完成.在0.1 mol·-1,的H3PO4中浸泡5 rain,可实现该传感器的良好再生.结果表明,毒莠定的检测下限达到了10-10mol·L-1,线性区间为10-10～10-4mol·L-1,适合饮用水中毒莠定浓度的检测要求.

Liposome Immunosensor for Picloram in Water Based on Electrochemical Polymerization

A "sandwich-type" immunosensor for the determination of picloram in water environment was developed based on the immunoliposomes prepared by crosslinking rabbit antibody against picloram (anti-picloram) and potassium ferrocyanide-encapsulated liposomes with glutaraldehyde. The working conditions including modification components on the electrode were optimized. The best performance is obtained using 0.5% of Nafion, 10 mg x mL(-1) of multiwalled carbon nanotubes (MWCNTs) and 50 microg x mL(-1) of anti-picloram. The preparation and detection process of immunosensor was as follows. Cyclic voltammetry was applied to urge the electrochemical polymerization of 3,4-ethylenedioxythiophene (EDOT) and the anti-picloram was immobilized on the modified glassy carbon electrode (GCE). Then the electrode was incubated with the analytes and immunoliposomes sequentially. The bound liposomes were lysed with TritonX-100, and square-wave voltammetry was applied to determine current response of picloram concentration. The whole process was able to be completed in 70 min. The immunosensor has good reproductivity after being soaked in 0.1 mol x L(-1) of H3PO4 in 5 min. The result shows that lower detection limit for picloram is 10(-10) mol x L(-1) with linear range of 10(-10)-10(-4) mol x L(-1), which meets the detection requirement of picloram for the safety of drinking water.