title: A "turn-off" fluorescent biosensor for the detection of mercury (II) based on graphite carbon nitride.
abstract: A novel and simple fluorescent biosensor has been realized through the fluorescence quenching of graphite carbon nitride (g-C3N4) for mercuric ion (Hg2+) detection. In this assay, the g-C3N4sheets which were functionalized with single-stranded DNA (ssDNA) aptamer showed strong fluorescence emission at 440nm under the excitation of 380nm in the absence of Hg2+. When added to the assay solution, Hg2+was embedded in the hairpin-shaped double-stranded DNA (dsDNA) due to the formation of the thymine-Hg2+-thymine (T-Hg2+-T) complex, which made the Hg2+close to the surface of g-C3N4sheet. Therefore, the fluorescence of g-C3N4was quenched. This sensor has good selectivity with a limit of detection as low as 0.17nM under optimal conditions. The present work demonstrates that the g-C3N4-based fluorescent sensor has a promising application for detection of metal ions in real samples.
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
authors.forename: Jingshuai
authors.initials: J
authors.lastname: Li
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
authors.forename: Huan
authors.initials: H
authors.lastname: Wang
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
authors.forename: Zhankui
authors.initials: Z
authors.lastname: Guo
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
authors.forename: Yaoguang
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
authors.forename: Hongmin
authors.initials: H
authors.lastname: Ma
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Ren
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
authors.forename: Bin
authors.initials: B
authors.lastname: Du
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China. Electronic address: sdjndxwq@163.com.
authors.forename: Qin
authors.initials: Q
authors.lastname: Wei
mesh_terms: D001483:Base Sequence; D015374:Biosensing Techniques / Q000379:methods*; D004247:DNA / Q000737:chemistry; D004277:DNA, Single-Stranded / Q000737:chemistry; D005453:Fluorescence; D006108:Graphite / Q000737:chemistry*; D008628:Mercury / Q000032:analysis*; D008854:Microscopy, Electron; D009570:Nitriles / Q000737:chemistry*; D015203:Reproducibility of Results; D013050:Spectrometry, Fluorescence; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D004277:DNA, Single-Stranded; D009570:Nitriles; D014874:Water Pollutants, Chemical; C011206:cyanogen; D006108:Graphite; D004247:DNA; D008628:Mercury
keywords: Aptamer; Fluorescent biosensor; Graphite carbon nitride; Mercuric ion