Structural diversity of lanthanide–amino acid complexes under near physiological pH conditions and their recognition of single-stranded DNA

Abstract

We reported here four structures of lanthanide–amino acid complexes obtained under near physiological pH conditions and their individual formula can be described as [Tb 2( dl-Cys) 4(H 2O) 8]Cl 2 ( 1), [Eu 4(μ 3-OH) 4( l-Asp) 2( l-HAsp) 3(H 2O) 7] Cl · 11.5H 2O ( 2), [Eu 8( l-HVal) 16(H 2O) 32]Cl 24 · 12.5H 2O ( 3), and [Tb 2( dl-HVal) 4(H 2O) 8]Cl 6 · 2H 2O ( 4). These complexes showed diverse structures and have shown potential application in DNA detection. We studied the interactions of the complexes with five single-stranded DNA and found different fluorescence enhancement, binding affinity and binding stoichiometry when the complexes are bound to DNA.