title: Fabrication of an antibody-aptamer sandwich assay for electrochemical evaluation of levels of β-amyloid oligomers.
abstract: Amyloid β-peptide (Aβ) in its oligomeric form is often considered as the most toxic species in Alzheimer's disease (AD), and thus Aβ oligomer is a potentially promising candidate biomarker for AD diagnosis. The development of a sensitive and reliable method for monitoring the Aβ oligomer levels in body fluids is an urgent requirement in order to predict the severity and progression at early or preclinical stages of AD. Here, we show a proof of concept for a sensitive and specific detection of Aβ oligomers by an antibody-aptamer sandwich assay. The antibodies of Aβ oligomers and a nanocomposite of gold nanoparticles with aptamer and thionine (aptamer-Au-Th) were used as the recognition element and the detection probe for specifically binding to Aβ oligomers, respectively. The electrochemical signal of Th reduction could provide measurable electrochemical signals, and a low limit of detection (100 pM) was achieved due to the signal amplification by high loading of Th on the gold nanoparticles. The feasibility of the assay was verified by test of Aβ oligomers in artificial cerebrospinal fluid. The proposed strategy presents valuable information related to early diagnosis of AD process.
authors.affiliation: Henan Key Laboratory of Biomolecular Recognition and Sensing, College of Chemistry and Chemical Engineering, Shangqiu Normal University, Shangqiu 476000, P. R. China.|College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou 450001, P. R. China.
authors.forename: Yanli
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou 450001, P. R. China.
authors.forename: Huanqing
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Henan Key Laboratory of Biomolecular Recognition and Sensing, College of Chemistry and Chemical Engineering, Shangqiu Normal University, Shangqiu 476000, P. R. China.
authors.forename: Lantao
authors.initials: L
authors.lastname: Liu
authors.affiliation: College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou 450001, P. R. China.
authors.forename: Congming
authors.initials: C
authors.lastname: Li
authors.affiliation: Henan Key Laboratory of Biomolecular Recognition and Sensing, College of Chemistry and Chemical Engineering, Shangqiu Normal University, Shangqiu 476000, P. R. China.
authors.forename: Zhu
authors.initials: Z
authors.lastname: Chang
authors.affiliation: Henan Key Laboratory of Biomolecular Recognition and Sensing, College of Chemistry and Chemical Engineering, Shangqiu Normal University, Shangqiu 476000, P. R. China.
authors.forename: Xu
authors.initials: X
authors.lastname: Zhu
authors.affiliation: College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou 450001, P. R. China.
authors.forename: Baoxian
authors.initials: B
authors.lastname: Ye
authors.affiliation: Henan Key Laboratory of Biomolecular Recognition and Sensing, College of Chemistry and Chemical Engineering, Shangqiu Normal University, Shangqiu 476000, P. R. China.|College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou 450001, P. R. China.
authors.forename: Maotian
authors.initials: M
authors.lastname: Xu
mesh_terms: D000544:Alzheimer Disease / Q000175:diagnosis*; D016229:Amyloid beta-Peptides / Q000032:analysis*; D000906:Antibodies / Q000276:immunology; D052158:Aptamers, Peptide / Q000378:metabolism; D003955:Diagnostic Tests, Routine / Q000379:methods*; D055664:Electrochemical Techniques; D007118:Immunoassay / Q000379:methods*; D011485:Protein Binding
chemical_list: D016229:Amyloid beta-Peptides; D000906:Antibodies; D052158:Aptamers, Peptide