title: A simple and sensitive fluorescent sensing platform for Hg²+ ions assay based on G-quenching.
abstract: In this work, a novel fluorescence biosensor was demonstrated for detection of Hg(2+) ions with relatively high selectivity and sensitivity. The sensing scheme was based on G-quenching induced by Hg(2+) ions. In the presence of Hg(2+) ions, the single-stranded signal probe which has carboxylfluorescein (FAM) and guanine segment at its 5' and 3' ends, respectively, folded into duplex-like structure via the Hg(2+)-mediated coordination of T-Hg(2+)-T base pairs. It brought guannine segment close to the dye and caused a remarkable decrease of fluorescence signal. The sensor showed a sensitive response to Hg(2+) ions in a concentration range from 0.5 to 10 μM, and a detection limit of 0.5 nM was given. This homogeneous system required only a single-labeled oligonucleotide, operated by concise procedures, and possessed comparable sensitivity as previous approaches. Furthermore, the sensor exhibits a great perspective for future practical applications.
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, Jilin, PR China.
authors.forename: Peng
authors.initials: P
authors.lastname: Hu
authors.forename: Lihua
authors.initials: L
authors.lastname: Jin
authors.forename: Chengzhou
authors.initials: C
authors.lastname: Zhu
authors.forename: Shaojun
authors.initials: S
authors.lastname: Dong
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D005452:Fluoresceins / Q000737:chemistry; D005453:Fluorescence; D006147:Guanine / Q000737:chemistry*; D007477:Ions / Q000032:analysis; D057230:Limit of Detection; D008628:Mercury / Q000032:analysis*; D009841:Oligonucleotides / Q000737:chemistry
chemical_list: D005452:Fluoresceins; D007477:Ions; D009841:Oligonucleotides; C024098:6-carboxyfluorescein; D006147:Guanine; D008628:Mercury