title: "Off-On" based fluorescent chemosensor for Cu2+ in aqueous media and living cells.
abstract: A novel Cu(2+)-specific "off-on" fluorescent chemosensor of naphthalimide modified rhodamine B (naphthalimide modified rhodamine B chemosensor, NRC) was designed and synthesized, based on the equilibrium between the spirolactam (non-fluorescence) and the ring-opened amide (fluorescence). The chemosensor NRC showed high Cu(2+)-selective fluorescence enhancement over commonly coexistent metal ions or anions in neutral aqueous media. The limit of detection (LOD) based on 3×δ(blank)/k was obtained as low as 0.18 μM of Cu(2+), as well as an excellent linearity of 0.05-4.5 μM (R=0.999), indicating the chemosensor of high sensitivity and wide quantitation range. And also the coordination mode with 1:1 stoichiometry was proposed between NRC and Cu(2+). In addition, the effects of pH, co-existing metal ions and anions, and the reversibility were investigated in detail. It was also demonstrated that the NRC could be used as an excellent "off-on" fluorescent chemosensor for the measurement of Cu(2+) in living cells with satisfying results, which further displayed its valuable applications in biological systems.
authors.affiliation: Key Laboratory of Coastal Zone Environmental Processes, CAS, Shandong Provincial Key Laboratory of Coastal Zone Environmental Processes, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China.
authors.forename: Chunwei
authors.initials: C
authors.lastname: Yu
authors.forename: Lingxin
authors.initials: L
authors.lastname: Chen
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
authors.forename: Jinhua
authors.initials: J
authors.lastname: Li
authors.forename: Ping
authors.initials: P
authors.lastname: Liu
authors.forename: Wenhai
authors.initials: W
authors.lastname: Wang
authors.forename: Bing
authors.initials: B
authors.lastname: Yan
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D003300:Copper / Q000032:analysis* / Q000737:chemistry; D000431:Ethanol / Q000737:chemistry; D006367:HeLa Cells; D006801:Humans; D006863:Hydrogen-Ion Concentration; D015394:Molecular Structure; D053644:Naphthalimides / Q000737:chemistry; D015203:Reproducibility of Results; D012235:Rhodamines / Q000737:chemistry; D012996:Solutions / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods*; D014867:Water / Q000737:chemistry
chemical_list: D053644:Naphthalimides; D012235:Rhodamines; D012996:Solutions; D014867:Water; D000431:Ethanol; D003300:Copper; C029773:rhodamine B