The next revolution in in-vitro bioaffinity assays will be associated with the minimization of the liquid phase of an experiment and with the extremely rapid detection of a large number of samples. The ultra detection unit is one of the essential elements of such devices. The fluorescence detection systems are most promising. The fluorescence detection limit of europium ions is as low as 10(-15) M in the complex with beta-diketone. The authors' approach to designing new highly effective chelates is to synthesize a stable chelate wherein several molecules of beta-diketones are properly oriented and chemically fixed. The molecular mechanic calculation of three dimensional structure of different Eu chelates should be used in optimizing the strategy of chemical synthesis of new compounds. New chelates can be efficiently used for the development of a new approach to measuring distances equal to over 10 nm in the biological systems. Pesticides also represent challenging targets because the levels of compounds are to be detects in minor concentrations, thus the time-resolution fluorescence assay may have some advantages due to its high sensitivity. DNA-based microbiochips are the most promising area in the practical use of a new chelate. A novel europium chelate is a key compound for the development of new methods for studying biological and chemical objects, as well as new diagnostic systems based on a basically new instrumental base that is characterized by extremely high miniaturization.