title: "Turn-on" fluorescent sensor for Hg2+ via displacement approach.
abstract: A new Cu2+ compound Cu- NB, (where H2 NB is bis(2-hydroxyl-naphthalene-carboxaldehyde) benzil dihydrazone) was synthesized as a highly selective fluorescence chemosensor for the detection of Hg2+ in aqueous media through a displacement "turn-on" signaling strategy. Whereas the coordination of Cu2+ resulted in a considerable quenching of the typical luminescence of the naphthol rings in Cu-NB, the addition of Hg2+ ion led to a dramatic increase in the emission intensity of Cu-NB at about 530 nm (excitation at 430 nm). The competitive fluorescent experiments showed that alkali, alkaline earth metal ions, the group 12 metals Zn2+, Cd2+, the first-row transition-metal ions such as Mn2+, Fe2+, Co2+, and Ni2+, as well as Pb2+ could not inhibit the Hg2+-binding fluorescent enhancement. It is postulated that the existence of Cu2+ in the luminescent probe Cu-NB could turn away the interferences of other metal cations from Hg2+ detection. The optical responses of the free ligand upon addition of Cu2+ ion, and of the Hg-H2NB compound upon the addition of Cu2+ were also investigated for comparisons.
authors.affiliation: State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian, China.
authors.forename: Guangjie
authors.initials: G
authors.lastname: He
authors.forename: Yonggang
authors.initials: Y
authors.lastname: Zhao
authors.forename: Cheng
authors.initials: C
authors.lastname: He
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.forename: Chunying
authors.initials: C
authors.lastname: Duan
mesh_terms: D003300:Copper / Q000737:chemistry; D018360:Crystallography, X-Ray; D005456:Fluorescent Dyes / Q000737:chemistry*; D006835:Hydrazones / Q000138:chemical synthesis* / Q000737:chemistry; D008628:Mercury / Q000032:analysis* / Q000737:chemistry*; D015394:Molecular Structure; D009281:Naphthalenes / Q000138:chemical synthesis* / Q000737:chemistry; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D012996:Solutions / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D005456:Fluorescent Dyes; D006835:Hydrazones; D009281:Naphthalenes; D009942:Organometallic Compounds; D012996:Solutions; C530896:bis(2-hydroxyl-naphthalene-carboxaldehyde) benzil dihydrazone; D014867:Water; D003300:Copper; D008628:Mercury