Issue 1, 2014

Cascade signal amplification for ultrasensitive electrochemical DNA detection

Abstract

In this work, by integrating multiple signal enhancement approaches, a new cascade signal amplification strategy is described to achieve highly sensitive electrochemical DNA detection. The presence of the target DNA leads to the unfolding of the biotin-modified hairpin probes on the sensor surface. With the addition of the primer sequences and polymerase, the target DNA is recycled and reused through isothermal strand-displacement polymerase reactions (ISDPR) to unfold a large number of the probes, which offer numerous binding sites to capture alkaline phosphatase (ALP)-loaded nanoparticle labels. These surface captured ALP enzymes catalyze the conversion of p-aminophenylphosphate to p-aminophenol, which generates amplified catalytic current responses due to the redox-recycling process during the potential sweep in the presence of the co-reactant NADH. With the synergistic signal amplifications by ISDPR-assisted target recycling, multi-ALP enzyme labels and redox-recycling, the proposed method offers highly sensitive detection of DNA down to 0.1 fM with single-base discrimination capability. Due to the significantly high sensitivity, the developed cascade signal amplification strategy can be potentially extended to detect various DNA targets at ultralow levels for early diagnoses of different diseases.

Graphical abstract: Cascade signal amplification for ultrasensitive electrochemical DNA detection

Article information

Article type
Paper
Submitted
04 Sep 2013
Accepted
09 Oct 2013
First published
09 Oct 2013

Analyst, 2014,139, 128-132

Cascade signal amplification for ultrasensitive electrochemical DNA detection

J. Xu, Q. Wang, Y. Xiang, R. Yuan and Y. Chai, Analyst, 2014, 139, 128 DOI: 10.1039/C3AN01673K

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