The sensitive determination of nucleic acids using fluorescence enhancement of Eu3+-benzoylacetone-cetyltrimethylammonium bromide-nucleic acid system.

A new quantitative method for micro amounts of nucleic acids in aqueous solution is proposed using Eu3+-benzoylacetone (BA) complex as fluorescent probe in the presence of cetyltrimethyl-ammonium bromide (CTMAB). Under the optimum condition, the ratio of the fluorescence intensities with and without nucleic acids is proportional to the concentration of nucleic acid in the range of 1.0x10(-9) to 5.0x10(-6) g/mL for herring sperm DNA (hsDNA), 3.0x10(-9) to 1.0x10(-6) g/mL for calf thymus DNA(ctDNA) and 8.0x10(-9) to 1.0x10(-6) g/mL for yeast RNA (yRNA), and their detection limits are 0.33, 0.21 and 0.99 ng/mL, respectively. Actual sample (DNA of Arabidopsis thaliana) was determined satisfactorily. In addition, the interaction mechanism is also investigated.