Hemin/G-quadruplex DNAzyme nanowires amplified luminol electrochemiluminescence system and its application in sensing silver ions. Issue 43 (14th April 2016)

• Record Type: Journal Article
• Authors: Liu, Guangpeng; Yuan, Yali; Wang, Jianli
• Is Part Of: RSC advances. Volume 6:Issue 43(2016)
• Page Start: 37221
• Page End: 37225
• Publication Date: 2016-04-14
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c6ra01809b
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : Herein, a DNA biosensor with a hemin/G-quadruplex DNAzyme amplified luminol electrochemiluminescence (ECL) system was constructed for sensing silver ions (Ag + ). Abstract : Herein, a DNA biosensor with a hemin/G-quadruplex DNAzyme amplified luminol electrochemiluminescence (ECL) system was constructed for sensing silver ions (Ag + ). The cytosine (C)-rich capture DNA was first assembled on an electrodeposited gold nanoparticle (dep Au)-modified electrode. With specific base-pairing, the primer DNA was assembled on the electrode, which thus triggered hybridization chain reaction (HCR) to in situ produce long hemin/G-quadruplex DNAzyme nanowires. In the electrolyte containing H2 O2 and luminol, the hemin/G-quadruplex exhibited superior horseradish peroxidase (HRP)-like activity and catalyzed H2 O2 to quickly produce abundant reactive oxygen species (ROSs), which could greatly enhance the ECL intensity of luminol. Since Ag + could mediate the C–C mismatch to form a stable C–Ag + –C complex between two neighboring C-rich capture DNA, the DNA nanochains gradually moved away from the electrode with the increase of Ag + concentration, which resulted in a decreased ECL intensity for quantitative detection. According to the experimental results, the proposed DNA biosensor showed a linear range from 2 pM to 20 μM and exhibited excellent sensitivity and selectivity in the detection of Ag + .