基于AuNPs/PDDA-GO纳米复合物的电化学免疫传感器的构建及对SirT1蛋白的检测

基于AuNPs/PDDA-GO纳米复合物制备了一种新型电化学免疫传感器, 并将其用于SirT1的检测. 首先, 在电极表面修饰复合材料AuNPs/PDDA-GO, 然后将目标蛋白SirT1固定到修饰了AuNPs/PDDA-GO的电极表面, 再通过特异性免疫反应结合一抗(Ab₁)和辣根过氧化酶标记的二抗分子(HRP-Ab₂), 最后用示差脉冲伏安法检测电流信号, 实现了对SirT1蛋白水平的测定. 在优化的实验条件下, SirT1蛋白的浓度在0.1~100 ng/mL范围内与响应电流呈良好线性关系, 检出限为0.029 ng/mL.

Electrochemical Immunosensor Based on AuNPs/PDDA-GO for Detection of SirT1

AuNPs/PDDA-GO nanocomposite was produced by combining poly(diallyldimethylammonium chloride)(PDDA) functionalized graphene oxide nanosheets(PDDA-GO) and gold nanoparticles(AuNPs) through self-assembly method, which offered an efficient platform for antibody immobilization with good biocompatibility. A new type of electrochemical immunosensor based on AuNPs/PDDA-GO nanocomposite for the detection of SirT1 was then developed. The immunosensor construction consisted of the immobilization of the hybrid architecture, the immunoreaction of target antigen SirT1 and capture antibody(Ab1), followed by the binding of HRP-Ab2. The designed immunoassay showed an excellent analytical performance, and exhibited a wide dynamic response range for SirT1 from 0.1 ng/mL to 100 ng/mL with a detection limit of 0.029 ng/mL. Overall, this developed strategy is proved as a simple, cost-effective method, and can be easily extended to other protein analysis.