| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1241699 | Talanta | 2016 | 5 Pages |
•We report a label-free and simple electrochemical biosensor for Hg2+ detection.•DNAzyme was formed through Hg2+ mediated DNA hybridization and ligase ligation.•This biosensor exhibited excellent selectivity against other metal ions.
A novel label-free electrochemical biosensor for the detection of Hg2+ based on ligase mediated creation of G-quadruplex-hemin DNAzyme has been developed. Firstly, Cp probe was immobilized on the gold electrode surface through Au–SH bond. In the presence of Hg2+, Cp and Ap probes were partly hybridized with the LJ probe respectively through the specific T–Hg2+–T interaction. Then, the adjacent 3′-OH terminal of Cp will link with the 5′-PO4 terminal of Ap to form a G-rich DNA at the function of T4-ligase. After interaction with hemin, the G-rich DNA can form a G-quadruplex–hemin HRP-mimicking DNAzyme. Through measuring the current change caused by DNAzyme-catalyzed oxidation of 3,3′,5,5′-tetramethylbenzidine(TMB), sensitive detection of Hg2+ can be achieved. The proposed sensor is simple, sensitive and selective, without the need of complicated labeling process, thus holds great potential for routine analysis of Hg2+ in environmental and biological samples.
Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide
