Synthesis of multi-channel fluorescence probes
Prof. Vasyl G. Pivovarenko
Scientific direction on the synthesis of multi-channel fluorescence probes was initiated at the organic chemistry chair by Vasyl G. Pivovarenko in 1994. A strategy was the design of the compounds displaying a multi-color fluorescence, which are capable to change dramatically their fluorescence parameters (band intensity, band position etc.) upon the changes of the nature of surrounding molecules. In such a case the fluorescence parameters form separate channels for registration of the events in the object on the molecular scale.
Even first synthesized compound – 4’-(15-azacrown-5)-3-hydroxyflavone (1) has displayed unique sensor properties – the ability in acetonitrile solution to distinguish the cations of different radii (H+, Mg2+ and Ba2+), giving a different fluorescence response upon binding the cation with one of three receptors present in the molecule. The second compound – bis-crownketocyanine (2) was able not only to distinguish these cations, but also demonstrated additionally record on the amplitude shifts of the bands of metal complexes in the absorption and fluorescence spectra. Later the synthesized series of 3-hydroxyflavones and ketocyanines were utilized in the study of intermolecular interactions in solutions and in lipid membranes. It was shown for ketocyanine dyes the possibility of fluorometric detection of hydrogen bonded complexes with one and two molecules of hydrogen bond donor (HBD), and for 3-hydroxyflavone dyes – the possibility of fluorometric detection of HBD concentration in the low polar solvent. In addition, insensitive to HBD compound 3 was synthesized that created a possibility of fluorometric detection of the polarity level effected by non-specific interactions in the solutions. Resolving of such complex problem became possible due to the application of multi-channel fluorescence probes.
Among other results there are wide-range fluorescent pH indicators (4, 5, each – for ðÍ-measurements in the range on 3 to 11), unique of known dye with three macrocyclic cation receptors (6), a probe for study the membrane dipole potential (7), and recently displayed a possibility of resolving of a new task – the measurement of hydrogen bond acceptor ability of organic medium on the basis of fluorescent properties of 3-hydroxyquinolone dyes (8 and 9). Last time more attention was paid to the fluorescent labeling of peptides and proteins by the developed ultrasensitive dyes (10, 11), that allows to obtain a new information about the peptide-peptide, peptide-protein and peptide-nucleic acid interactions. However, as a main achievement in the direction of multi-channel fluorescence probes design should be mentioned the created possibility of selective detection of adenosine thriphosphate (ATP) in aqueous solutions by the fluorescent probes of 3-hydroxyflavone nature (dyes 1, 5, 7 etc.), that can be possible to do even in the presence of close on the structure anions such as ADP, AMP, GTP, UTP or ITP etc.
The group has close and numerous contacts with the laboratories of scientific institutions of Ukraine and other countries. As a result, the graduates of Chemistry faculty of KNTSU (master and PhD students or postdocs) now work in the best laboratories of the world. Among them: A.S. Klymchenko, D.A. Yushchenko, V.V. Shvadchak, V.Yu. Postupailenko, O.A. Kucherak, D.M. Dzyuba.