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DNAzyme sensor for the detection of Ca2+ using resistive pulse sensing

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journal contribution
posted on 29.10.2020, 11:24 by Imogen Heaton, Mark Platt
DNAzymes are DNA oligonucleotides that can undergo a specific chemical reaction in the presence of a cofactor. Ribonucleases are a specific form of DNAzymes where a tertiary structure undergoes cleavage at a single ribonuclease site. The cleavage is highly specificity to co-factors, which makes them excellent sensor recognition elements. Monitoring the change in structure upon cleavage has given rise to many sensing strategies; here we present a simple and rapid method of following the reaction using resistive pulse sensors, RPS. To demonstrate this methodology, we present a sensor for Ca2+ ions in solution. A nanoparticle was functionalised with a Ca2+ DNAzyme, and it was possible to follow the cleavage and rearrangement of the DNA as the particles translocate the RPS. The binding of Ca2+ caused a conformation change in the DNAzyme, which was monitored as a change in translocation speed. A 30 min assay produced a linear response for Ca2+ between 1–9 µm, and extending the incubation time to 60 min allowed for a concentration as low as 0.3 µm. We demonstrate that the signal is specific to Ca2+ in the presence of other metal ions, and we can quantify Ca2+ in tap and pond water samples.

Funding

Nuclear Decommissioning Authority

History

School

  • Science

Department

  • Chemistry

Published in

Sensors

Volume

20

Issue

20

Publisher

MDPI AG

Version

VoR (Version of Record)

Rights holder

© The Authors

Publisher statement

This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).

Acceptance date

10/10/2020

Publication date

2020-10-17

Copyright date

2020

ISSN

1424-8220

eISSN

1424-8220

Language

en

Depositor

Dr Mark Platt. Deposit date: 27 October 2020

Article number

5877

Licence

Exports

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Licence

Exports