title: Highly sensitive and selective detection of Hg2+ using mismatched DNA and a molecular light switch complex in aqueous solution.
abstract: A novel "signal-on" assay for sensitive and selective detection of Hg(2+) in aqueous solution based on mismatched DNA and a molecular light switch complex, [Ru(phen)(2)(dppz)](2+), was reported in the present work. This Hg(2+) specific sensor system composed of two label-free DNA probes with eight T-T mismatches, which could form stable DNA duplexes by thymine-Hg(2+)-thymine (T-Hg(2+)-T) in the presence of Hg(2+). The luminescence of [Ru(phen)(2)(dppz)](2+) is very weak in aqueous solution, and significant luminescence can be observed when intercalating into DNA duplexes. By monitoring Hg(2+)-dependent luminescence intensity enhancement, highly sensitive and selective determination of Hg(2+) has been achieved. Under the optimum conditions, the luminescence intensity was proportional to the concentration of Hg(2+) in the range of 1.0x10(-9)-1.5x10(-7) M. A detection limit of 3.5x10(-10) M Hg(2+) was achieved using 3sigma. The presence of other metal ions did not interfere with the detection of Hg(2+) even at high concentrations. This approach is simple and rapid, which can be used to monitor the Hg(2+) concentration in drinking water and natural media within 30 min.
authors.affiliation: Key Laboratory of Eco-chemical Engineering, Ministry of Education, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao, China.
authors.forename: Xiaoru
authors.initials: X
authors.lastname: Zhang
authors.forename: Ying
authors.initials: Y
authors.lastname: Li
authors.forename: Haoran
authors.initials: H
authors.lastname: Su
authors.forename: Shusheng
authors.initials: S
authors.lastname: Zhang
mesh_terms: D020137:Base Pair Mismatch; D015374:Biosensing Techniques / Q000295:instrumentation*; D004247:DNA / Q000737:chemistry*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008163:Luminescent Measurements / Q000295:instrumentation*; D008628:Mercury / Q000032:analysis* / Q000737:chemistry; D015336:Molecular Probe Techniques / Q000295:instrumentation*; D009942:Organometallic Compounds / Q000032:analysis / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D009942:Organometallic Compounds; C466600:Ru(phen)(2)dipyrido(3,2-a-2',3'-c)phenazine; D004247:DNA; D008628:Mercury