Binding of EuIII to 1,2-Hydroxypyridinone-Modified Peptide Nucleic Acids

Substitution of a nucleobase pair with a pair of 1,2-hydroxypyridinone (1,2-HOPO) ligands in the center of a 10-base-pair peptide nucleic acid (PNA) duplex provides a strong binding site for Eu-III as evidenced by UV thermal melting curves, UV titrations, and luminescence spectroscopy. Eu-III excitation spectra and luminescence lifetime data are consistent with Eu-III bound to both 1,2 HOPO ligands in a PNA-HOPO duplex as the major species present in solution.