CLAUDIA AKEMI KODAIRA GOES

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  • Resumo IPEN-doc 16168
    Potential applications for the use of rare earth complexes and nanoparticles as luminescent biolabels
    2010 - FELINTO, M.C.F.C.; KODAIRA, C.A.; PAGANINI, P.P.; SANTOS, E.G.; LOURENCO, A.V.S.; BRITO, H.F.; NUNES, L.A.O.; MALTA, O.L.; SANCHES, E.; GIDLUND, M.; GOTO, H.; BRITO, M.E.F.
    The ever growing interest in rare earth coordination compounds and materials wilh optical properties stems from applications in multidisciplinar fields such as nanosensors, materials for telecommunications. lighting devices, and luminescent probes for bioanalyses and live cell imaging and sensing. Most of these applications use the unique ability of lhe rare earth ions to emit well-defined narrow bands in different spectral ranges, from visible to near-infrared. Due to the low absorption cross-section of the f.f transitions, efficient population of lhe excited 4f states has to rely on energy transfer from the surroundings of Ihe metal ion (antena effect or luminescence sensitization). Another point desirable is the use of RE3+ ions wilh emission in the near-infrared (NIR) region reducing !he interference from biological materials in the analyses. In this work. we report the preparation and characterization of rare earth coordination compounds and nanoparticles based on rare earth ions. RE3+ beta-diketonate complexes with macrocyclic ligand has been synthesized and characterized and are being used to mark hemoglobin S (sickle cells) Leishmania (tropical disease) and PSA (Prostate-specific antigen that is a protein produced by cells of the prostate gland. The PSA test measures the level of PSA in the blood). Several nanoparticles based on Nd3+, Eu3+ and Tb3+ ions doped into the Y2O3 matrix. are also being synthesized and evaluated for labeling anti-oxLDL (anti-oxidized low density lipoproteins), one of the principal causes of cardiovascular diseases and responsible for around 30% of deaths world-wide. information about struture and average grain size of these nanoparticles were obtained by x-ray diffration (XRDJ, transmission electron micrograph (TEM) and infrared absorption spectroscopy.
  • Artigo IPEN-doc 15132
    Using lanthanide chelates and uranyl compounds for diagnostic by fluoroimmunoassays
    2009 - SANTOS, ELEN G.; TOMIYAMA, CLAUDIA S.; KODAIRA, CLAUDIA A.; LOURENCO, ANA V.S.; FELINTO, MARIA C.F.C.; BRITO, HERMI F.; BRITO, MARIA E.F.
    The importance of the luminescence of lanthanide ions and UO2 2+ is related to its peculiar characteristics, e.g. long lifetime and line-like emission bands in the visible, which make these ions unique among the species that are known to luminescence. Recent developments in the field of supramolecular chemistry have allowed the design of ligands capable of encapsulating lanthanide ions, thus forming kinetically inert complexes. By introduction of chromophoric groups in these ligands, an intense luminescence of the ion can be obtained via the "antenna effect", defined as a light conversion process involving distinct absorbing (ligand) and emitting (metal ion) components. In such a process, the quantities that contribute to the luminescence intensity are (i) the efficiency of the absorption, (ii) the efficiency of the ligand-metal energy transfer, and (iii) the efficiency of the metal luminescence. Encapsulation of lanthanide ions with suitable ligands may therefore give rise to "molecular devices" capable to emit strong, long-lived luminescence. Besides the intrinsic interest in their excited state properties, compounds of lanthanide ions, in particular of the Eu3+ and Tb3+ ions, and now UO2 2+ are important for their potential use as luminescent labels for biological species in fluoroimmunoassays (FIAs). This is most interesting because fluorimetric labeling represents an alternative method to the use of radioactive labels, which has long been the most common way of quantifying immunoreactions. In this article we report information about luminescent materials, which gave a good signal to quantify biological molecules by TR-FIA, DELFIA , DSLFIA, RIA and FRET.