Leonenko I. Determination of some bioactive substances by quenching effect on the sensibilized luminescence of lanthanide ions

The thesis is devoted to search of new analytical forms based on terbium (III) complex with oxyquinoline carboxylic acid pyridinamides derivatives (L1-6) and carboxylated crown ethers (L7,8) for the determination of some bioactive substances (drugs, proteins, alkaline metal ions) with the use of quenching effect on the 4f-luminescence of lanthanide ion. Spectrophotometric and the acid-base characteristics of reagents, quantum yields and lifetimes of lanthanide complexes were determined. The maximum intensity of the luminescence of complexes is observed in water solutions without addition of organic solvents, surfactants and synergetic agents. Relationship of the luminescent characteristics of europium (III) and terbium (III) complexes with the structure of ligands has been established through 2D-QSРR models for the row of oxyquinoline carboxylic acid amides derivatives. The received models (symplex, circular and consensus) indicate priority influence on the quantum yield of luminescence and lifetime of the excited state of lanthanide ions of electrostatic and Van-der-Waals interactions. It has been established that introduction of some medicinal preparations to the Tb(III)-L1-5 (1:1) system leads to the quenching effect on the 4f-luminescence of terbium (III) ions as a result of formation of adduct between ligand-sensitizer and quencher. High-sensitivity, simple and express methods of determination of proteins: human serum albumin, immunoglobulin, bovine serum albumin and hemoglobine with the detection limits 0.03 ?g/ml have been developed on the basis of complex Tb(III)-L6 (6-[(1-hydroxy-3-oxo-6,7-dihydro-3H,5H-pyrido[3,2,1-ij]quinoline-2-carbonyl)-amino]-hexanoic acid). It has been established that introduction of alkaline metal ions to the Tb(III)-carboxylated crown ethers system leads to the quenching of luminescence and reducing of lifetime of the excited state of terbium ions, that can be confirmation of the formation of Tb(III)-L7,8-Na+(K+) complexes. The method of selective determination of Na+ ions in the presence of 1000-multiple excess of K+ ions has been developed by the system of Tb(III)-4-carboxybenzo-15-crown-5 (L7). Keywords: complexes, terbium, sensibilized luminescence, luminescence quenching, determination of bioactive substances.