Issue 2, 2019

Transition metal-coordinated graphitic carbon nitride dots as a sensitive and facile fluorescent probe for β-amyloid peptide detection

Abstract

Herein, we developed a sensitive graphitic carbon nitride quantum dot (gCNQD)-based fluorescent strategy for β-amyloid peptide monomer (Aβ) determination down to the ng mL−1 level for the first time. To realize this goal, the nanostructured gCNQDs were firstly coordinated with four transition metal ions (Cu2+, Cu+, Fe3+, Zn2+). Our findings showed that the fluorescence (FL) intensity of gCNQDs was quenched in the presence of these metal ions possibly due to the effective chelation with the nitrogen element in gCNQDs and subsequent photoinduced electron transfer (PET) of gCNQDs. The degree of fluorescence quenching was found to be the most intense with the addition of Cu2+ and therefore, we selected Cu2+ as the quencher for the following Aβ determination. Through binding to Cu2+, the introduction of Aβ unexpectedly induced a further decline of FL intensity. Importantly, on account of different peptide sequences coexisting in the same cerebral system, including Aβ1–11, Aβ1–16, Aβ1–38, Aβ1–40 and Aβ1–42, their affinities to Cu2+ could be reflected by the distinguished declining extent of FL intensity. The possible mechanism of Aβ sensing by the probe was clarified by TEM characterization. The developed fluorescent biosensor was demonstrated to give a wide linear range from 1 to 700 ng mL−1 and a low detection limit of 0.18 ng mL−1 for Aβ1–42. In the end, the proposed fluorescence approach was successfully applied to monitoring of Aβ1–42 variations in the cortex and hippocampus of AD rats.

Graphical abstract: Transition metal-coordinated graphitic carbon nitride dots as a sensitive and facile fluorescent probe for β-amyloid peptide detection

Supplementary files

Article information

Article type
Paper
Submitted
21 8 2018
Accepted
01 11 2018
First published
02 11 2018

Analyst, 2019,144, 504-511

Transition metal-coordinated graphitic carbon nitride dots as a sensitive and facile fluorescent probe for β-amyloid peptide detection

Y. Zhang, S. Meng, J. Ding, Q. Peng and Y. Yu, Analyst, 2019, 144, 504 DOI: 10.1039/C8AN01620H

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements