Star trigon structure-aided DNA walker for amplified electrochemical detection of DNA

Abstract

Synthetic artificial DNA probes are excellent architectural scaffolds which can be assembled into various nanostructures for further applications. A DNA walker is usually designed in response to certain external stimuli, and can significantly enhance the obtained signals. Herein, we have developed a novel DNA walker biosensor for the detection of target DNA with enzymatic recycling cleavage. By using the target DNA as a driving force, a DNA star trigon nanostructure is formed on the electrode surface, which can be recognized by a nicking endonuclease. The DNA walker is then activated to move around for the cleavage reactions on the electrode. The resulting DNA biosensor shows excellent analytical performance with a low limit of detection of 1 fM. Good selectivity and practical utility are also demonstrated. This approach has many other advantages such as ease of use, low cost, mild conditions, and may hold great potential for a range of applications in the future. Keywords: DNA walker, DNA star trigon, Nicking endonuclease, Square wave voltammetry, Signal amplification