Novel Fluorescent Chelate for Eu

摘要

Novel high efficient fluorescent chelate for Eu based on diethylenethriaminepentaacetic acid and amino β-diketones is proposed for time-resolved fluorescence immunoassay (TR-FIA). The label surpasses all known chelates for europium in major spectral and luminescent characteristics. The proposed label has number of advantages over the well-known europium chelates. The assays with new fluorescent chelate do not require enhancement solution, but the sensitivity of Eu determination is the same as for DELFIA enhancement solution. The assay with new fluorescent chelate is insensitive to contamination of solutions and samples with ions of heavy metals, because the concentration of fluorescent chelate is measured and high excess of Eu prevents dissociation of fluorescent chelate complex. Techniques have been developed for covalent labelling of proteins with the new fluorescent chelate. The labelling proteins can be stored in the lyophilised state or in stabilised solution rather long and retain their immunological properties. Application of the new fluorescent chelate enables the washing step to be avoided and to develop the express non-separation assay.