title: Electrochemical Detection of Amyloid-β Oligomers Based on the Signal Amplification of a Network of Silver Nanoparticles.
abstract: Amyloid-β oligomers (AβOs) are the most important toxic species in the brain of Alzheimer's disease (AD) patient. AβOs, therefore, are considered reliable molecular biomarkers for the diagnosis of AD. Herein, we reported a simple and sensitive electrochemical method for the selective detection of AβOs using silver nanoparticles (AgNPs) as the redox reporters and PrP(95-110), an AβOs-specific binding peptide, as the receptor. Specifically, adamantine (Ad)-labeled PrP(95-110), denoted as Ad-PrP(95-110), induced the aggregation and color change of AgNPs and the follow-up formation of a network of Ad-PrP(95-110)-AgNPs. Then, Ad-PrP(95-110)-AgNPs were anchored onto a β-cyclodextrin (β-CD)-covered electrode surface through the host-guest interaction between Ad and β-CD, thus producing an amplified electrochemical signal through the solid-state Ag/AgCl reaction by the AgNPs. In the presence of AβOs, Ad-PrP(95-110) interacted specifically with the AβOs, thus losing the capability to bind AgNPs and to induce the formation of an AgNPs-based network on the electrode surface. Consequently, the electrochemical signal decreased with an increase in the concentration of AβOs in the range of 20 pM to 100 nM. The biosensor had a detection limit of 8 pM and showed no response to amyloid-β monomers (AβMs) and fibrils (AβFs). On the basis of the well-defined and amplified electrochemical signal of the AgNPs-based network architecture, these results should be valuable for the design of novel electrochemical biosensors by marrying specific receptors.
authors.affiliation: Henan Province of Key Laboratory of New Optoelectronic Functional Materials, College of Chemistry and Chemical Engineering, Anyang Normal University , Anyang, Henan 455000, People's Republic of China.
authors.forename: Ning
authors.initials: N
authors.lastname: Xia
authors.affiliation: Henan Province of Key Laboratory of New Optoelectronic Functional Materials, College of Chemistry and Chemical Engineering, Anyang Normal University , Anyang, Henan 455000, People's Republic of China.
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.affiliation: Henan Province of Key Laboratory of New Optoelectronic Functional Materials, College of Chemistry and Chemical Engineering, Anyang Normal University , Anyang, Henan 455000, People's Republic of China.
authors.forename: Binbin
authors.initials: B
authors.lastname: Zhou
authors.affiliation: Henan Province of Key Laboratory of New Optoelectronic Functional Materials, College of Chemistry and Chemical Engineering, Anyang Normal University , Anyang, Henan 455000, People's Republic of China.
authors.forename: Yangyang
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Henan Province of Key Laboratory of New Optoelectronic Functional Materials, College of Chemistry and Chemical Engineering, Anyang Normal University , Anyang, Henan 455000, People's Republic of China.
authors.forename: Wenhui
authors.initials: W
authors.lastname: Mao
authors.affiliation: Henan Province of Key Laboratory of New Optoelectronic Functional Materials, College of Chemistry and Chemical Engineering, Anyang Normal University , Anyang, Henan 455000, People's Republic of China.
authors.forename: Lin
authors.initials: L
authors.lastname: Liu
mesh_terms: D000544:Alzheimer Disease / Q000175:diagnosis*; D016229:Amyloid beta-Peptides / Q000032:analysis*; D015374:Biosensing Techniques / Q000379:methods*; D055664:Electrochemical Techniques; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*
chemical_list: D016229:Amyloid beta-Peptides; D012834:Silver
keywords: amyloid-β oligomers; colorimetric assay; electrochemical biosensors; host−guest interaction; peptide; silver nanoparticles