title: pH-sensitive fluorescent sensors based on europium(III) complexes.
abstract: New europium(III) complexes Eu(TTA)(2)-DSQ and Eu(TTA)(3)-DR1 were designed and synthesized as new fluorescent pH probes (where HDSQ = 5-(dimethylamino)-N-(4-(2-((8-hydroxyquinolin-2-yl)methylene)hydrazinecarbonyl)phenyl)naphthalene-1-sulfonamide, DR1 = N(1)-(4-(dimethylamino)benzylidene)-N(2)-(rhodamine-6G) lactamethylene-diamine and TTA = thiophentrifluoroacetone). Eu(TTA)(2)-DSQ exhibited high sensitivity in monitoring pH changes in neutral aqueous solution with negligible background fluorescence. Eu(TTA)(3)-DR1 comprised a green light emitting Rhodamine 6G fluorophore and a Eu(III) moiety as the origin of red light. These pH-sensitive emitter components have pK(a) values of 5.0 and 7.2 respectively, and exhibit isolated protonated steps within one molecule. Luminescence titrations demonstrate that Eu(TTA)(3)-DR1 was able to detect pH values at both near neutral pH and acidic pH ranges, and was also able to detect pH in both cultured cells and in vivo.
authors.affiliation: State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian, 116012, China.
authors.forename: Xiaolin
authors.initials: X
authors.lastname: Zhang
authors.forename: Yang
authors.initials: Y
authors.lastname: Jiao
authors.forename: Xu
authors.initials: X
authors.lastname: Jing
authors.forename: Hongmei
authors.initials: H
authors.lastname: Wu
authors.forename: Guangjie
authors.initials: G
authors.lastname: He
authors.forename: Chunying
authors.initials: C
authors.lastname: Duan
mesh_terms: D000818:Animals; D015374:Biosensing Techniques; D003461:Crystallography; D005063:Europium / Q000737:chemistry*; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000737:chemistry*; D006367:HeLa Cells; D006801:Humans; D006863:Hydrogen-Ion Concentration; D015394:Molecular Structure; D015027:Zebrafish
chemical_list: D005456:Fluorescent Dyes; D005063:Europium