title: A tripod ligand as new sensitiser for the enzyme amplified lanthanide luminescence determination of esterase.
abstract: Screening of a small library of tripod ligands resulted in the discovery of bis(2-pyridylmethyl)-(2-hydroxybenzyl)amine (HL1) as a new sensitiser, which is able to transfer its excitation energy to terbium(III). After synthesis of the acetic acid ester of HL1, a highly selective method for the determination of porcine liver esterase by means of enzyme amplified lanthanide luminescence (EALL) was developed. Enzyme-catalysed cleavage of the ester results in the formation of HL1. After excitation at 297 nm, the characteristic emission of Tb(III) at 545 nm is observed and used to determine the esterase concentration. In contrast to existing EALL methods, this method may be carried out at neutral pH and without further additives. Limit of detection for porcine liver esterase is 10(-9) mol l(-1) and limit of quantification is 3 x 10(-9) mol l(-1). A linear calibration range of two decades starting at the limit of quantification is observed.
authors.affiliation: University of Twente, Department of Chemical Analysis and MESA+ Research Institute, P.O. Box 217, 7500 AE Enschede, The Netherlands.
authors.forename: Tanja
authors.initials: T
authors.lastname: Steinkamp
authors.forename: Florian
authors.initials: F
authors.lastname: Schweppe
authors.forename: Bernt
authors.initials: B
authors.lastname: Krebs
authors.forename: Uwe
authors.initials: U
authors.lastname: Karst
mesh_terms: D000818:Animals; D004950:Esterases / Q000032:analysis*; D008024:Ligands; D008099:Liver / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods; D013552:Swine; D013725:Terbium
chemical_list: D008024:Ligands; D013725:Terbium; D004950:Esterases