title: NO fluorescence sensing by europium tetracyclines complexes in the presence of H2O2.
abstract: The effect on the fluorescence of the europium:tetracycline (Eu:Tc), europium:oxytetracycline (Eu:OxyTc) and europium:chlortetracycline (Eu:ClTc) complexes in approximately 2:1 ratio of nitric oxide (NO), peroxynitrite (ONOO(-)), hydrogen peroxide (H2O2) and superoxide (O2 (·-)) was assessed at three ROS/RNS concentrations levels, 30 °C and pH 6.00, 7.00 and 8.00. Except for the NO, an enhancement of fluorescence intensity was observed at pH 7.00 for all the europium tetracyclines complexes-the high enhancement was observed for H2O2. The quenching of the fluorescence of the Tc complexes, without and with the presence of other ROS/RNS species, provoked by NO constituted the bases for an analytical strategy for NO detection. The quantification capability was evaluated in a NO donor and in a standard solution. Good quantification results were obtained with the Eu:Tc (3:1) and Eu:OxyTc (4:1) complexes in the presence of H2O2 200 μM with a detection limit of about 3 μM (Eu:OxyTc).
authors.affiliation: Centro de Investigação em Química da Universidade do Porto, Porto, Portugal.
authors.forename: Eliana F C
authors.initials: EF
authors.lastname: Simões
authors.forename: João M M
authors.initials: JM
authors.lastname: Leitão
authors.forename: Joaquim C G
authors.initials: JC
authors.lastname: Esteves da Silva
mesh_terms: D002623:Chemistry Techniques, Analytical / Q000295:instrumentation*; D005063:Europium / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000032:analysis* / Q000737:chemistry; D009569:Nitric Oxide / Q000032:analysis* / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013754:Tetracyclines / Q000737:chemistry*
chemical_list: D009942:Organometallic Compounds; D013754:Tetracyclines; D009569:Nitric Oxide; D005063:Europium; D006861:Hydrogen Peroxide