title: Terbium (III) chelate complexes as fluorescence energy transfer donor in the determination of formaldehyde in aqueous solutions.
abstract: The sensitized fluorescence intensity of the terbium (III) ion can be notably enhanced in the presence of sodium hexametaphosphate (SHMP). Based on this, water-soluble Tb-SHMP chelate complexes were synthesized in aqueous solutions, and characterized by spectrofluorometry. 6-Mercapto-5-triazole[4,3-b]-S-tetrazine was generated by the quantitative reaction of HCHO with 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole under alkaline conditions at room temperature. The spectral overlap between the emission of Tb-SHMP chelate complexes and absorption of 6-mercapto-5-triazole[4,3-b]-S-tetrazine meets the prerequisite for fluorescence energy transfer. Based on this, a novel efficient fluorescence energy transfer system between Tb-SHMP chelate complexes as donor and 6-mercapto-5-triazole[4,3-b]-S-tetrazine as acceptor was developed for the determination of HCHO in aqueous solutions. Under the optimal experimental conditions, this method is capable of detecting HCHO concentrations from 2.06×10(-5) to 6.18×10(-3) mg mL(-1) and the limit of detection was 7.11×10(-6) mg mL(-1). Compared with other general methods for the determination of HCHO, the proposed method improved the sensitivity and selectivity. Moreover, the proposed method was successfully applied to the determination of HCHO in water samples.
authors.affiliation: Anhui Key Laboratory of Chemo-Biosensing, College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000, PR China.
authors.forename: Hongqi
authors.initials: H
authors.lastname: Chen
authors.forename: Cailing
authors.initials: C
authors.lastname: Zhou
authors.forename: Lun
authors.initials: L
authors.lastname: Wang
authors.forename: Jingguo
authors.initials: J
authors.lastname: Chen
authors.forename: Bo
authors.initials: B
authors.lastname: Ling
authors.forename: Jie
authors.initials: J
authors.lastname: Fu
mesh_terms: D002614:Chelating Agents / Q000737:chemistry*; D004735:Energy Transfer; D005557:Formaldehyde / Q000032:analysis*; D007477:Ions; D010710:Phosphates / Q000737:chemistry; D012996:Solutions; D013050:Spectrometry, Fluorescence; D013438:Sulfhydryl Compounds / Q000737:chemistry; D013696:Temperature; D013725:Terbium / Q000737:chemistry*; D013997:Time Factors; D014867:Water / Q000737:chemistry*
chemical_list: D002614:Chelating Agents; D007477:Ions; D010710:Phosphates; D012996:Solutions; D013438:Sulfhydryl Compounds; D014867:Water; D013725:Terbium; C006537:4-amino-5-hydrazino-1,2,4-triazole-3-thiol; D005557:Formaldehyde; C009285:sodium polymetaphosphate