Dulplex analysis of mercury and silver ions using a label-free fluorescent aptasensor |
| |
| Authors: | Juan Zhang Yafei Huang Jiao Yan Chao Zhu Ailiang Chen |
| |
| Institution: | 1. Institute of Quality Standards and Testing Technology for Agro-products, Key Laboratory of Agro-product Quality and Safety, Chinese Academy of Agricultural Sciences, Beijing, China;2. Key Laboratory of Agri-food Quality and Safety, Ministry of Agriculture, Beijing, China;3. College of Food Science and Technology, Hainan University, Haikou, China |
| |
| Abstract: | Label-free Hg2+ aptamer was used as a sensing element and the PicoGreen dye was specific to ultra-sensitive double-stranded DNA (dsDNA), which achieved novel fluorescence assay for detection of both mercury and silver ions. In this aptasensor, Hg2+ bound to thymidine (T) to form T–Hg2+-T base pairs and Ag+ specifically interacted with C–C mismatches to produce C–Ag+–C base pairs. The conformation changes prevented the aptamer from binding to its complementary sequences to form dsDNA and caused a fluorescence intensity decrease with PicoGreen. The change in the fluorescence intensity made it possible to detect both Hg2+ and Ag+ in a dose-dependent manner. The sensing system could detect as low as 5 × 10–8 mol/L of Hg2+ and 9.3 × 10–10 mol/L of Ag+. The fluorescent intensity changes in the system were specific for Hg2+ and Ag+, making this simple and cost-effective method extremely valuable in its future applications in monitoring Hg2+ and Ag+ pollution in environmental analysis. |
| |
| Keywords: | Aptamer PicoGreen mercury silver label-free aptasensor |
|
|
