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 (ΔS) and enthalpy (ΔH) 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.