Issue 46, 2018

Pyrophosphate ion-triggered competitive displacement of ssDNA from a metal–organic framework and its application in fluorescent sensing of alkaline phosphatase

Abstract

Nanomaterial/aptamer assembly has been extensively explored in the detection of various targets, but some limitations still exist in its practical applications, especially time consumption and low-efficient detachment of the aptamer from the nanomaterial surface. In this work, we demonstrated the ligand role of pyrophosphate ion (PPi) in the competitive displacement of ssDNA from the nanoscaffold surface. For this purpose, a fluorescein-labeled ssDNA (F-DNA) and a mixed valence state cerium (Ce3+/Ce4+)-based MOF (MVCM) were employed as the signal response unit and nanoscaffold, respectively. Benefiting from the existence of Ce4+, the MVCM exhibits an ultrahigh quenching efficiency (more than 90%) to F-DNA fluorescence, which is 3-fold higher than that of the MOF with Ce3+ only. However, it was found that PPi can effectively suppress the quenching effect of the MVCM by competitive coordination with the MVCM to displace F-DNA. Different from the conventional target-induced conformational change of aptamers, the PPi-triggered displacement assay is independent of the ssDNA sequence and can be rapidly completed in just 2 min. The displacement assay is also highly sensitive, even at a PPi concentration as low as 55 nM. In contrast to PPi, however, the phosphate ions and other anions cannot displace F-DNA from the MVCM surface to switch on the F-DNA fluorescence. Inspired by this fact, the PPi-triggered displacement assay was further applied in the detection of alkaline phosphatase (ALP). The detection limit toward ALP was obtained at 0.18 mU mL−1. Moreover, the accurate determination of ALP concentration in serum samples indicates the applicability of this sensing system in detecting real samples.

Graphical abstract: Pyrophosphate ion-triggered competitive displacement of ssDNA from a metal–organic framework and its application in fluorescent sensing of alkaline phosphatase

Supplementary files

Article information

Article type
Paper
Submitted
18 Aug 2018
Accepted
12 Oct 2018
First published
15 Oct 2018

J. Mater. Chem. B, 2018,6, 7614-7620

Pyrophosphate ion-triggered competitive displacement of ssDNA from a metal–organic framework and its application in fluorescent sensing of alkaline phosphatase

C. Wang, G. Tang and H. Tan, J. Mater. Chem. B, 2018, 6, 7614 DOI: 10.1039/C8TB02175A

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