Time-resolved fluorescence sensing of N-acetyl amino acids, nucleobases, nucleotides and DNA by the luminescent Tb (III) - 8-alkyl-2-oxo-2H-chromene-3-carbaldehyde probe

A time-resolved (gated) luminescence-based method for the detection of some of N-acetyl amino acids, nucleobases, nucleotides, and DNA using terbium- 8-alkyl-2-oxo-2H-chromene-3-carbaldehyde (AOCC) complex in 1:2 metal: ligand ratio in microtiterplate format has been evolved. The linear range for determination of the selected biomolecules is 0.1–1.0 µM. The detection limit was in the range of 0.0371–0.106 µM. The thermodynamic parameters, and binding constants ( K ) of N-acetyl amino acids, nucleobases, nucleotides with Tb (III) –(AOCC) 2 complex were calculated. Positive and negative values of entropy (Δ S ) and enthalpy (Δ H ) changes for Tb (III) –(AOCC) 2 – N-acetyl amino acids, nucleobases or nucleotides ternary complexes were evaluated. Selectivity of Tb (III) -complex towards different biomolecules has been studied using ratiometric methods of analysis by comparison of biomolecules binding affinities for Tb (III) -complex. Interaction of Tb (III) complex with DNA has been studied.