Synthesis of novel Eu(III) luminescent probe based on 9- acridinecarboxylic acid skelton for sensing of ds-DNA.

Eu(III)-9-acridinecarboxylate (9-ACA) complex was synthesized and characterized by elemental analysis, conductivity measurement, IR spectroscopy, thermal analysis, mass spectroscopy, (1)H-NMR, fluorescence and ultraviolet spectra. The results indicated that the composition of this complex is [Eu(III)-(9-ACA)(2)(NCS)(C(2)H(5)OH)(2)] 2.5 H(2)O and the oxygen of the carbonyl group coordinated to Eu(III). The interaction between the complex with nucleotides guanosine 5'- monophosphate (5'-GMP), adenosine 5'-diphosphates (5'-ADP), inosine (5'-IMP) and CT-DNA was studied by fluorescence spectroscopy. The fluorescence intensity of Eu(III)-9-acridinecarboxylate complex was enhanced with the addition of CT-DNA. The effect of pH values on the fluorescence intensity of Eu(III) complex was investigated. Under experimental conditions, the linear range was 9-50 ng mL(-1) for calf thymus DNA (CT- DNA) and the corresponding detection limit was 5 ng mL(-1). The results showed that Eu(III)-(9-ACA)(2) complex binds to CT-DNA with stability constant of 2.41 × 10(4) M.