Synthesis of a novel fluorescent probe based on acridine skeleton used for sensitive determination of DNA

In this study, a novel fluorescent probe of acridine-derivitive N-((N-(2-dimethylamino)ethyl)acridine-4-carboxamide)-alpha-alanine (N-(ACR-4-CA)(alpha-ALA) was synthesized. The structure of the new compound was characterized by H-1 NMR, MS, elemental analysis, fluorescent and ultraviolet spectra. It was found that DNA had the ability to quench the fluorescence of N-(ACR-4-CA)-alpha-ALA, and the quenched intensity of fluorescence was proportional to the concentration of DNA. A method for DNA determination based on the quenching fluorescence (lambda(ex) = 260 nm, lambda(cm) = 451 nm) of N-(ACR-4-CA)-alpha-ALA was established. Under optimal conditions, the linear range is 0.05-2.0 mu g mL(-1) for both fish semen (fsDNA) and calf thymus DNA (ctDNA). The corresponding determination limits are 9.1 ng mL(-1) for fsDNA and 8.7 ng mL(-1) for ctDNA, respectively. The results suggested that the interaction mode between N-(ACR-4-CA)-alpha-ALA and DNA was intercalative binding. The intrinsic binding constant was determined and the result showed a large binding constant of N-(ACR-4-CA)-alpha-ALA with DNA. (c) 2008 Elsevier B.V. All rights reserved.