检出限
材料科学
化学
电化学
电极
生物传感器
石墨烯
线性范围
分析化学(期刊)
组合化学
微分脉冲伏安法
电化学气体传感器
循环伏安法
作者
Yulan Wang,Hongmin Ma,Xiaodong Wang,Xuehui Pang,Dan Wu,Bin Du,Qin Wei
标识
DOI:10.1016/j.bios.2015.06.033
摘要
Abstract An ultrasensitive sandwich-type electrochemical immunosensor based on a novel signal amplification strategy was developed for the quantitative determination of human immunoglobulin G (IgG). Pd nanocubes functionalized magnetic graphene sheet (Pd–Fe 3 O 4 -GS) was employed as the matrix to immobilize the primary antibodies (Ab 1 ). Owing to the synergetic effect between Pd nanocubes and magnetic graphene sheet (Fe 3 O 4 -GS), Pd–Fe 3 O 4 -GS can provide an obviously increasing electrochemical signal by electrochemical catalysis towards hydrogen peroxide (H 2 O 2 ). Silicon dioxide (SiO 2 ) was functionalized as the label to conjugate with the secondary antibodies (Ab 2 ). Due to the larger steric hindrance of the obtained conjugate (SiO 2 @Ab 2 ), the sensitive decrease of the electrochemical signal can be achieved after the specific recognition between antibodies and antigens. In this sense, this proposed immunosensor can achieve a high sensitivity, especially in the presence of low concentrations of IgG. Under optimum conditions, the proposed immunosensor offered an ultrasensitive and specific determination of IgG down to 3.2 fg/mL. This immunoassay method would open up a new promising platform to detect various tumor markers at ultralow levels for early diagnoses of different cancers.
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