title: Label-free selective sensing of mercury(II) via reduced aggregation of the perylene fluorescent probe.
abstract: In the present work, we report a fluorescence turn-on approach for the sensitive and selective detection of Hg(2+). A cationic perylene derivative (compound 1) was used as the fluorescence probe, and a thymine-rich oligonucleotide (oligo-M) was employed for the specific interaction with Hg(2+). Compound 1 shows strong tendency to self-aggregate into linear chain structures in aqueous media because of the pi-pi stacking interactions of its planar aromatic ring structure. The compound 1 free monomer is strongly fluorescent, whereas its aggregates are not fluorescent. When oligo-M and compound 1 were mixed, oligo-M induced strong compound 1 aggregation and resulted in significant fluorescence quenching. In the presence of Hg(2+), the specific interactions between oligo-M and Hg(2+) induced hairpin structure formation of oligo-M and thus weakened its binding to compound 1 aggregates. As a result, free probe monomers were released, and increased fluorescence was observed. The fluorescence intensity increase was in direct proportion to the concentration of Hg(2+) added. Our method provides a simple, fast, and efficient means for Hg(2+) quantification, it is highly sensitive with a limit of detection of 1 nM, and is also highly selective against other common metal ions.
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China.
authors.forename: Bin
authors.initials: B
authors.lastname: Wang
authors.forename: Fangyuan
authors.initials: F
authors.lastname: Wang
authors.forename: Huping
authors.initials: H
authors.lastname: Jiao
authors.forename: Xiangyu
authors.initials: X
authors.lastname: Yang
authors.forename: Cong
authors.initials: C
authors.lastname: Yu
mesh_terms: D005453:Fluorescence; D005456:Fluorescent Dyes / Q000737:chemistry*; D008628:Mercury / Q000032:analysis*; D010084:Oxidation-Reduction; D010569:Perylene / Q000737:chemistry*
chemical_list: D005456:Fluorescent Dyes; D010569:Perylene; D008628:Mercury