Issue 12, 2019

DNAzyme-based biosensor as a rapid and accurate verification tool to complement simultaneous enzyme-based media for E. coli detection

Abstract

Simultaneous enzyme-based media can be used to identify both coliforms and E. coli faster than lactose-based fermentation protocols. However, these media can be prone to false-positive results and would require verification tests to confirm the presence of E. coli. These verification tests (e.g. indole or oxidase tests) work based on identifying specific phenotypic traits in bacteria, and hence are also prone to inaccuracies. This study aimed to achieve rapid verification test of E. coli using DNAzyme-based biosensor. The biosensor was first tested for four E. coli strains against more than 90 non-E. coli strains routinely causing false positive results and showed high specificity towards E. coli strains. The biosensor was then determined for its detection sensitivity. It was observed that a single E. coli colony would generate a robust fluorescence signal after 2 h of sub-culturing. With this short incubation time, non-E. coli strains were unable to generate any apparent fluorescence signal, hence further improving the detection specificity of biosensor. Lastly, we further demonstrate that the biosensor can be applied to different commercial brands of simultaneous enzyme-based agar to consistently identify the presence of E. coli. The biosensor was able to rapidly denote presence of discrete E. coli colonies by binding on to protein targets possibly of DNA replication or motility functions that were predominantly specific to E. coli.

Graphical abstract: DNAzyme-based biosensor as a rapid and accurate verification tool to complement simultaneous enzyme-based media for E. coli detection

Supplementary files

Article information

Article type
Paper
Submitted
09 Sep 2019
Accepted
21 Oct 2019
First published
22 Oct 2019
This article is Open Access
Creative Commons BY license

Environ. Sci.: Water Res. Technol., 2019,5, 2260-2268

DNAzyme-based biosensor as a rapid and accurate verification tool to complement simultaneous enzyme-based media for E. coli detection

N. Zaouri, Z. Cui, A. S. Peinetti, Y. Lu and P. Hong, Environ. Sci.: Water Res. Technol., 2019, 5, 2260 DOI: 10.1039/C9EW00795D

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements