化学
免疫分析
电极
胶体金
生物传感器
纳米技术
DNA
检出限
纳米颗粒
组合化学
抗体
色谱法
材料科学
生物化学
物理化学
生物
免疫学
作者
Chao Deng,Manman Zhang,Chunyan Liu,Honghua Deng,Yan Huang,Minghui Yang,Juan Xiang,Bin Ren
出处
期刊:Analytical Chemistry
[American Chemical Society]
日期:2018-09-04
卷期号:90 (19): 11446-11452
被引量:12
标识
DOI:10.1021/acs.analchem.8b02556
摘要
Current strategies for high-performance immunoassay generally require a sandwich structure for signal amplification. This strategy is limited to multivalent antigens and complicates the detection scheme. Herein we demonstrate a class of simple one-step ultrasensitive immunoassay with the adoption of double-stranded DNA (dsDNA) as “conductive spring” to bridge the electrode and redox-reporter/antibody-receptor comodified gold nanoparticles (AbFc@AuNPs). Upon biorecognition between antigen and antibody, the charge of the AuNPs changes, enhancing the electrostatic interaction between the AuNPs and Au electrode surface, and condensing the dsDNA chain. For the first time, the sensitive response of the electrochemical redox current to the DNA chain length is utilized to achieve an ultrahigh sensitivity down to fM level. Only the primary antibody needed in the recognition interface ensures the one-step immunoreaction works well with monovalent antigens, which ensure this method as a promising general alternative means for fast, high-throughput or point-of-care clinical applications even for very challenging clinically relevant samples.
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