Luminescence properties of the Langmuir-Blodgett film of terbium(III) stearoylanthranilate

Terbium(III) stearoylanthranilate has been prepared as a high property Z-type Langmuir-Blodgett (LB) film on various substrates by a vertical transfer process. The UV-visible absorption spectra and the low angle X-ray diffraction peaks have been collected in order to investigate the molecular arrangement and aggregation in the LB films. The average molecular orientation in multilayer stacking was determined by Attenuated Total Reflection Spectroscopy. The influence of the chemical environment of terbium within the LB films on the luminescence properties has been discussed. (C) 1997 Elsevier Science S.A.

Luminescence properties of the ternary terbium complexes with (ortho and para) aminobenzoic acids and 1,10-phenanthroline incorporated in silica matrix by a sol-gel method

Ternary complexes of terbium with ortho (and pam) aminobenzoic acid and 1,10-phenanthroline were introduced into silica gel by the sol-gel method. The luminescence behavior of the solid-state samples was studied during the sol-gel aging process by means of emission. excitation spectra, lifetimes and quantum efficiencies.

Binary alloys of nylon 1010 and ethylene-propylene copolymer: Chemical, morphological, and mechanical analysis

The modification of ethylene-propylene copolymer (EPM) has been accomplished by melt grafting of maleic anhydride (MAH) molecules promoted by radical initiators. The resulting EPM-g-MAH and EPM have been used to obtain binary nylon 1010/EPM or nylon 1010/EPM-g-MAH blends by melt mixing. It was found that the EPM-g-MAH copolymer used as the second component has a profound effect upon the properties of the resulting blends. This behavior has been attributed to a series of chemical and physicochemical interactions taking place between the two components. The interactions are due to the presence of the anhydride functionality on the copolymer and do not occur when this functionality is absent. The interaction has been confirmed by Fourier-transform infrared spectroscopy, differential scanning calorimetry, dynamic mechanical analysis, and scanning electron microscopic.

ELECTRON-TRANSFER BETWEEN EU AND TB IN COMPLEX FLUORIDES

Europium (II) and europium (III) have been observed in MMgF(4):xEu, yTb (M=Ca, Sr, Ba) phosphors using their typical photoluminescence spectra when are synthesized in Ar or an Ar/H-2 stream. The valence state of Eu is influenced by terbium. It is notable that the intensities of the electron spin resonance peaks corresponding to Eu2+ change in a regular way when terbium ions are incorporated which can be explained by an electron transfer mechanism.

SOLVENT-EXTRACTION OF TERBIUM(III,IV) PERIODATE COMPLEXES WITH QUATERNARY AMINE

The differences between the solvent extraction of Tb(III) and Tb(IV) periodate complexes with quaternary amine were studied carefully for the first time. The effects of extractant concentration, phase ratio, the pH value of stock solution, salting-out agent, extractant form, diluent, and extraction time were comprehensively investigated. Under optimal conditions the separation factor between Tb(IV) and Tb(III) periodate complexes is over 5.5.

TERBIUM P-NITROBENZOATE HYDRATE

There are no discrete molecules of the title compound, catena-poly[{triaquaterbium-tris-beta-(p-nitro-benzoato)-O,O':O;O:O,O';O:O'-aqua(p-nitroben-zoato-O,O')terbium}-bis-mu-(p-nitrobenzoato-O:O') hydrate], [Tb2(C7H4NO4)6(H2O)5], in the crystal structure.

A homogeneous DNA hybridization system by using a new luminescence terbium chelate

Homogeneous DNA hybridization assay based on the luminescence resonance energy transfer (LRET) from a new luminescence terbium chelate, N,N,N-1,N-1-[2,6-bis(3'-aminomethyl-1'-pyrazolyl)-4-phenylpyridine]tetrakis(acetic acid) (BPTA)-Tb3+ (lambda(ex) = 325 nm and lambda(em) = 545 nm) to an organic dye, Cy3 (A,. = 548 nm and A,. = 565 nm), has been developed. In the system, two DNA probes whose sequences are complementary to the two different consecutive sequences of a target DNA are used; one of the probes is labeled with the Tb3+ chelate at the T-end, and the other is with Cy3 at the 5'-end. Labeling of the Tb3+ chelate is accomplished via the linkage of a biotin-labeled DNA probe with the Tb3+ chelate-labeled streptavidin. Strong sensitized emission of Cy3 was observed upon excitation of the Tb3+ chelate at 325 run, when the two probe DNAs were hybridized with the target DNA. The sensitivity of the assay was very high compared with those of the previous homogeneous-format assays using the conventional organic dyes; the detection limit of the present assay is about 30 pM of the target DNA strand.

Synthesis of a terbium fluorescent chelate and its application to time-resolved fluoroimmunoassay

A new nonadentate ligand, N, N, N-1, N-1-[2,6-bis(3'-aminomethyl-1 1'-pyrazolyl)-4-phenylpyridine]tetrakis(acetic acid) (BPTA) for a Tb3+ fluorescent complex was synthesized. The Tb3+ complex is strongly fluorescent, having a large fluorescence quantum yield of 1.00 and very long fluorescence lifetime of 2.681 ms in 0.05 M berate buffer of pH 9.1. Streptavidin (SA) was labeled with SPTA by using its succinimidyl monoester, and the BPTA-Tb3+-labeled SA was used in sandwich-type time-resolved fluoroimmunoassay (TR-FIA) of alpha -fetoprotein (AFP) and carcinoembryonic antigen (CEA) in human sera. The Tb3+-labeled SA was also used in competitive type TR-FIA of bensulfuron- methyl (BSM) in water. The detection limits of these assays are 42 pg/mL for AFP, 70 pg/mL for CEA, and 0.4 ng/mL for BSM. In addition, a new simultaneous measurement method for AFP and CEA in a human serum sample was developed by using 4,4'-bis(1 " ,1 " ,1 " ,2 " ,2 " ,3 " ,3 " -heptafluoro-4 " ,6 " -hexanedion-6 " -yl)chlorosulfo-o-terphenyl ((BHHCT)-Eu3+-labeled anti-AFP antibody, biotinylated anti-CEA antibody, and BPTA-Tb3+-labeled SA. The concentrations of AFP and CEA in 39 human serum samples were determined, and the results were compared with those of the independently determined AFP and CEA by TR-FIA with a single-label method. A good correlation was obtained with the correlation coefficients of 0.991 for AFP and 0.994 for CEA.

Homogeneous time-resolved fluoroimmunoassay of bensulfuron-methyl by using terbium fluorescence energy transfer

A sensitive homogenous time-resolved fluoroimmunoassay (TR-FIA) method for bensulfuron-methyl (BSM) based on fluorescence resonance energy transfer (FRET) from a Tb3+ fluorescent chelate with N,N,N',N'-[2,6-bis(3'-aminomethyl-1'-pyrazoly)-4-phenylpyridine] tetrakis(acetic acid) (BPTA-Tb3+) to organic dye, Cy3 or Cy3.5 has been developed. New method combined the use of BPTA-Tb3+ labeled streptavidin, Cy3 or Cy3.5 labeled anti-BSM monoclonal antibody and biotinylated BSM-BSA conjugate (BSA is bovine serum albumin) for competitive-type immunoassay. After BPTA-Tb3+ labeled streptavidin was reacted with a competitive immune reaction solution containing biotinylated BSM-BSA, BSM sample and Cy3 or Cy3.5 labeled anti-BSM monoclonal antibody, the sensitized and long-lived emission of Cy3 or Cy3.5 derived from FRET was measured, and thus the concentration of BSM in sample was calculated. The present method has the advantages of rapidity, simplicity and high sensitivity since the B/F (bound reagent/free reagent) separation steps and the solid-phase carrier are not necessary. The method gives the detection limit of 2.10 ng ml(-1). The coefficient variations of the method are less than 1.5% and the recoveries are in the range of 95-105% for BSM water sample measurement. (C) 2001 Elsevier Science B.V. All rights reserved.