基于碳纳米管修饰玻碳电极的唾液sIgA可再生免疫传感器  

Renewable Salivary Secretory Immunoglobulin A (sIgA) Immunosensor Based on Carbon Nanotube Modified Glassy Carbon Electrode

作　　者：王艳[1] 甄生航[1] 朱洋[1] 谢国明[1] 

机构地区：[1]重庆医科大学检验系临床检验诊断学教育部重点实验室,重庆400016

出　　处：《分析测试学报》2011年第4期349-355,共7页Journal of Instrumental Analysis

基　　金：重庆市自然科学基金资助项目(CSTC2010BB5356)

摘　　要：将壳聚糖(CHI)分散的羧基化多壁碳纳米管(MWCNT)吸附到玻碳电极(GCE)表面,形成负电荷界面,利用静电吸附和金-氮(Au-N)、金-硫(Au-S)共价键作用将阳离子电子媒介体硫堇(THI)和纳米金颗粒(GNPs)层层自组装到电极表面,通过纳米金单层吸附唾液分泌性免疫球蛋白A(sIgA),最后用辣根过氧化物酶(HRP)封闭电极上的非特异性吸附位点,同时放大电流信号,构建了一种检测唾液sIgA的新型纳米免疫生物传感器。实验结果表明,该传感器具有良好的准确性和稳定性;检测线性范围为3.0～350.0μg/L,r=0.989 7;检出限(S/N=3)为1.5μg/L;电流值达95%稳态时间小于20 s;可用0.1 mol/L的甘氨酸再生8次。探讨了底物浓度、抗体浓度、孵育时间、温度、pH值及干扰物质对该传感器的影响。该免疫传感器灵敏度高、特异性好、方便可再生,可用于唾液sIgA的准确、快速检测,从而判断人体局部免疫状况。A novel amperometric immunosensor based on multi-wall carbon nanotubes （MWNTs）/ layer-by-layer（LBL） assembly of gold nanoparticles and thionine （GNPs- THI）/secretory immunoglobulin A （sIgA）/horseradish peroxidase （HRP） was developed for the detection of salivary secretory immunoglobulin A （ sIgA ）. The layer-by-layer （LBL） assembly of gold nanoparticles and thionine （ GNPs - THI） was assembled through electrostatic adsorption, Au - S and Au - N covalent bonds. Then the salivary anti - sIgA antibody was adsorbed by the formative monolayer of GNPs. Eventually, the horseradish peroxidase （HRP） was used to block the nonspecific adsorption sites on the modified glassy carbon electrode （GCE） and amplify the current signal at the same time. The immunosensor showed a high sensitivity to salivary sIgA with a detection limit （ S/N = 3 ） of 1.5 μg/L. The linear range was 3.0 -350.0 μg/L with correlation coefficient（r） of 0. 989 7. The response time achieved 95% of the steady state was less than 20 s. Also, the immunosensor had an excellent interference immunity to the interferents of immunoglobulin G （ IgG）, α-amylase and albumin, and the interference rates were -2. 13% , -2.85% and - 1.96% , respectively. The antigen - antibody complexes in the measurement were decollemented by 0. 1 mol/L of aminoacetic acid. The bioactivities of antigen and antibody were remained well after decollement and the biosensor could be recycled by aminoacetic acid for eight times. Some influence factors on the biosensor were investigated, such as the concentration of substrate and antibody, incubation time, interferents, temperature and pH. It can be used for accurate and fast detection of salivary sIgA to judge the impairment of the mucosal immune system of human owing to its high sensitivity, excellent specificity and convenient detection, and it can be easily regenerated.

关 键 词：分泌性免疫球蛋白A 免疫生物传感器 多壁碳纳米管 硫堇 

分 类 号：O657.1[理学—分析化学] O629.73[理学—化学]