title: Ultra-sensitive fluorescent sensor for Hg2+ based on a donor-acceptor-donor framework.
abstract: A new fluoroionophore [E-4,4'-di(N-(2-pyridyl)amino)stilbene, E1] with a donor-acceptor-donor framework, which features a central stilbene (acceptor) fluorophore and two terminal pyridylamino (donor) ionophores, is reported. The probe displays an ultrasensitive fluorescence quenching response toward Hg(2+) in H(2)O/THF. Coordination of Hg(2+) to E1 affords a 2:1 complex, enabling the detection of Hg(2+) at a concentration as low as 4.4 × 10(-14) M. The interactions between the two species have been thoroughly characterized with UV-vis absorption spectroscopy, fluorescence spectroscopy, and nuclear magnetic resonance spectroscopy. Density functional theory calculations provide further insights into the nature of the fluorescence quenching response. In contrast, a fluorescent molecule with the donor-acceptor architecture, E-4-(N-(2-pyridyl)amino)stilbene (E4), exhibits a greatly attenuated fluorescence quenching response toward Hg(2+).
authors.affiliation: Department of Polymer Science and Engineering, School of Chemistry and Chemical Engineering, State Key Laboratory of Coordination Chemistry, Nanjing National Laboratory of Microstructures, Nanjing University, Nanjing 210093, China.
authors.forename: Xingqiang
authors.initials: X
authors.lastname: Liu
authors.forename: Xin
authors.initials: X
authors.lastname: Shu
authors.forename: Xin
authors.initials: X
authors.lastname: Zhou
authors.forename: Xu
authors.initials: X
authors.lastname: Zhang
authors.forename: Jin
authors.initials: J
authors.lastname: Zhu
mesh_terms: D000465:Algorithms; D002413:Cations, Divalent / Q000032:analysis / Q000737:chemistry; D005456:Fluorescent Dyes / Q000138:chemical synthesis / Q000737:chemistry*; D005663:Furans / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008628:Mercury / Q000032:analysis* / Q000737:chemistry; D011789:Quantum Theory; D012996:Solutions / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D013267:Stilbenes / Q000138:chemical synthesis / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: C467074:4-(N,N-bis(2-pyridyl)amino)stilbene; D002413:Cations, Divalent; D005456:Fluorescent Dyes; D005663:Furans; D012996:Solutions; D013267:Stilbenes; D014867:Water; C018674:tetrahydrofuran; D008628:Mercury