快速检测阿尔茨海默标志蛋白(Tau)的阻抗生物传感器研究

An Impedance Biosensor for Rapid Detection of Alzheimer's Marker Protein(Tau)

通过构建自组装阻抗免疫传感器,对微量Tau蛋白进行检测,以达到辅助早期诊断阿尔茨海默病的目的。传感器通过以下步骤构建,将双功能分子3,3'-二硫代双(磺酸琥珀酰亚氨基丙酸酯,DTSSP)通过Au-S键修饰到金电极表面,通过烷磺基-氨基结合抗体39E10。利用免疫原理,通过抗原-抗体之间的吸附作用特异性结合捕获Tau蛋白,使用交流阻抗法进行表征,并通过循环伏安法验证。通过对DTSSP修饰时间及抗体浓度的优化,传感器对质量浓度为0.02~100μg/m L的Tau蛋白有检测信号,其中在0.2~20μg/m L质量浓度范围内具有良好线性关系,r^2为0.988 8,检出限为0.43 nmol/L,检测时间为15 min。自组装免疫传感器对Tau实现了特异性捕获,可作为AD临床检测的辅助手段。

In this paper,a self-assembled impedance immune sensor was constructed to detect trace Tau protein in order to achieve the purpose of early diagnosis on Alzheimer disease. The sensor was constructed and characterized by the following steps： the bifunctional molecule 3,3＇-dithiobis（sulfosuccinimidylpropionate）（DTSSP） was modified on the gold electrode surface through the Au-S bond,which was then conjugated with antibodies 39 E10 through the CO-NH. Tau protein was specifically captured by physisorption using immunoassay,characterized by AC impedance and verified by cyclic voltammetry. By optimizing the DTSSP modification time and antibody concentration,the sensor had a detection signal toward Tau protein of 0. 02-100 μg/mL,in which there existed a good linearity（r-2= 0. 988 8） in the concentration range of 0. 2-20 μg/mL with a detection limit of 0. 43 nmol/L. This immunosensor＇s specific capture ability for Tau could be used as a supplementary means for clinical detection on AD.