[Studies on a new fluorescence-enhanced system of nucleic acids-morin-Al(III)]

A fluorescence-enhanced system was developed for the determination of nucleic acids by using morin-aluminum(III) complex as a new fluorescent probe. In aqueous solution, morin-aluminum(III) complex showed maximum excitation and emission wavelengths at 420.0 nm and 532.8 nm, respectively, and its fluorescence could be greatly enhanced in the presence of nucleic acids. Under optimal conditions, the calibration graph was linear over the range 0.25-1.50 microg x mL(-1) for fish sperm DNA, 0.10-1.60 microg x mL(-1) for salmon sperm DNA, 0.25-2.00 microg x mL(-1) for calf thymus DNA and 0.25-2.00 microg x mL(-1) for yeast RNA. The corresponding detection limits are 3 ng x mL(-1), 2 ng x mL(-1), 2 ng x mL(-1) and 3 ng x mL(-1), respectively. Applied for the determination of nucleic acids in synthetic samples, the relative standard deviation for five replicates is less than 3.6%, and the recovery ranges from 93.3% to 107.9%. Additionally, the interaction mechanism of morin-aluminum(III) with nucleic acids is also discussed.