Jump to main content
Jump to site search


Combined determination of copper ions and β-amyloid peptide by a single ratiometric electrochemical biosensor

Author affiliations

Abstract

Copper ions (Cu2+) play a critical role in biological processes and are directly involved in β-amyloid peptide (Aβ) aggregation, which is responsible for the occurrence and development of Alzheimer's disease (AD). Therefore, combined determination of Cu2+ and Aβ in one analytical system is of great significance to understand the exact nature of the AD event. This work presents a novel ratiometric electrochemical biosensor for the dual determination of Cu2+ and Aβ1–42. This unique sensor is based on a 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulphonate) (ABTS) and poly(diallyldimethylammonium chloride) (PDDA)-bi functionalized single-walled carbon nanotubes (ABTS-PDDA/CNTs) composite. The inclusion of ABTS not only enhanced the sensitivity, but it also acted as an inner reference molecule to improve detection accuracy. The specific recognition of Cu2+ was realized by neurokinin B (NKB) coatings on the ABTS-PDDA/CNTs surface to form a [CuII(NKB)2] complex with Cu2+. The ABTS-PDDA/CNTs-NKB modified electrode also displayed an excellent electrochemical response toward the Aβ1–42 monomer, when a certain amount of the Aβ1–42 monomer was added to Cu2+-contained PBS buffer, which was due to the release of Cu2+ from the [CuII(NKB)2] complex through Aβ binding to Cu2+. Meanwhile, our work showed that Cu2+ bound Aβ1–42 was concentration-dependent. Consequently, the presented electrochemical approach was capable of quantifying two important biological species associated with AD by one single biosensor, with the detection limits of 0.04 μM for Cu2+ and 0.5 ng mL−1 for Aβ1–42, respectively. Finally, the ratiometric electrode was successfully applied for monitoring Cu2+ and Aβ1–42 variations in plasma and hippocampus of normal and AD rats.

Graphical abstract: Combined determination of copper ions and β-amyloid peptide by a single ratiometric electrochemical biosensor

Back to tab navigation

Supplementary files

Publication details

The article was received on 12 Oct 2017, accepted on 15 Nov 2017 and first published on 15 Nov 2017


Article type: Paper
DOI: 10.1039/C7AN01683B
Citation: Analyst, 2018, Advance Article
  •   Request permissions

    Combined determination of copper ions and β-amyloid peptide by a single ratiometric electrochemical biosensor

    Y. Yu, P. Wang, X. Zhu, Q. Peng, Y. Zhou, T. Yin, Y. Liang and X. Yin, Analyst, 2018, Advance Article , DOI: 10.1039/C7AN01683B

Search articles by author

Spotlight

Advertisements