title: Selective fluorescent probes based on CN isomerization and intramolecular charge transfer (ICT) for zinc ions in aqueous solution.
abstract: As the second most abundant transition-metal ion in the human body, Zn2+ plays crucial roles in many important biological processes; while in the environment, an excessive concentration of Zn2+ may reduce the soil microbial activity resulting in phytotoxic effects. Therefore, developing effective and sensitive detection method for Zn2+ has become crucially important and necessary both in life and environment science. Two new fluorescence probes, 2-((2-hydroxynaphthalen-1-yl)methyleneamino)-3-(1H-imidazol-5-yl) propanoic acid (2) and 2-hydroxy-2-((2-hydroxynaphthalen-1-yl) methyleneamino) acetic acid (3), were easily prepared by a one step reaction between 2-hydroxy-1-naphthaldehyde with histidine and serine, respectively, in ethanol. The optical properties of them were investigated by fluorescence spectra, which displayed specific and sensitive recognition to Zn2+ and especially avoided the interference of Cd2+ when they were tested against a range of physiological and environmentally relevant metal ions in aqueous solution. The responsive mechanism of the two probes to Zn2+ were involved both the CN isomerization and ICT, which were clarified by NBO charge analysis and the HOMO-LUMO energy gap calculation by using B3LYP/6-31G density functional theory.
authors.affiliation: State Key Laboratory of Supramolecular Structure and Materials, College of Physical Education, Jilin University, No. 2699 Qianjin Street, Changchun 130012, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Li
authors.forename: Feng
authors.initials: F
authors.lastname: Liu
authors.forename: Hong-Wei
authors.initials: HW
authors.lastname: Li
mesh_terms: D004735:Energy Transfer; D005456:Fluorescent Dyes / Q000737:chemistry*; D006801:Humans; D007093:Imidazoles / Q000737:chemistry*; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis*; D011422:Propionates / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D015032:Zinc / Q000032:analysis* / Q000737:chemistry*
chemical_list: C568107:2-((2-hydroxynaphthalen-1-yl)methyleneamino)-3-(1H-imidazol-5-yl) propanoic acid; D005456:Fluorescent Dyes; D007093:Imidazoles; D009942:Organometallic Compounds; D011422:Propionates; D015032:Zinc