基于红荧烯纳米材料构建电致化学发光免疫传感器用于灵敏检测β淀粉样蛋白的研究

The electrochemiluminescence immunosensor based on the rubrene nanomaterials for sensitive detection of amyloid-β protein

该实验合成了一种以红荧烯为发光体的纳米棒(SDS-Rub),并基于此构建了高灵敏的信号减小型电致化学发光(ECL)免疫传感器用于β淀粉样蛋白的检测。该实验以二氧化硅(SiO_2)为模版制备了二茂铁纳米微球(PAA/PEI-Fc),极大限度地提高了二茂铁的固载量,更加灵敏地猝灭ECL信号。首先,将红荧烯纳米材料修饰到玻碳电极表面,将制得的银纳米线滴涂到修饰了的电极上,用于固载一抗。利用牛血清白蛋白(BSA)封闭多余的活性位点后,将抗原(Ag)孵育到电极上。此时,该传感器检测到高的ECL信号。利用抗原抗体特异性结合,将二茂铁二抗复合物(Fc-Ab_2)孵育到电极上,由于二茂铁的猝灭作用,ECL信号降低。基于ECL信号的变化值与β淀粉样蛋白浓度的关系,实现定量检测。实验结果表明,在β淀粉样蛋白抗体浓度范围10 fg/mL^100 ng/mL,该传感器的检测限为3.2 fg/mL。

In this study,the rubrene nanomaterials were synthesized as a luminophor to construct the sensitive electrochemiluminescence（ECL） immunosensor for the detection of β-amyloid protein.The ferrocene nanoparticles（PAA/PEI-Fc） were prepared by using silica as template,which greatly improved the load capacity of the（PAA/PEIFc） to quench the ECL signal more sensitively.Firstly,the Rub NRs was decorated on the polished GCE,then,the silver nanowires were dropped on the electrode to immobilize the capture antibody（Ab_1）.After immobilizing with the BSA to block the active site,the Aβ antigen（Ag） was incubated.Finally,the secondary antibody bioconjugate（FcAb_2） was connected to the surface of the electrode because of the specific binding of antibody to antigen,which obtained a declining ECL signal.The results showed that there was a good linear relationship of the concentration ofβ-amyloid protein at the concentration range of 10 fg/mL^100 ng/mL,with the detection limit of 3.2 fg/mL.This work can also provide a new approach for ultrasensitive detection of Aβ.