Fluorescence Determination of DNA Using the Gatifloxacin-Europium(III) Complex

A method for the determination of DNA based on the fluorescence intensity of the gatifloxacin-europium(III) (GFLX-Eu3+) complex that could be enhanced by DNA was developed. The GFLX-Eu3+ complex showed an up to 6-fold enhancement of luminescence intensity after adding DNA. Under the optimized experimental conditions, the system exhibited a linear relationship between the enhanced fluorescence intensity and the concentration of calf thymus DNA (ctDNA) over the range from 1.0 x 10(-8) to 1.5 x 10(-6) g mL(-1), with a correlation coefficient (R) of 0.997, and the detection limit (3 sigma) of the method was determined as 6.0 x 10(-9) g mL(-1). The mechanism of the fluorescence enhancement effect was also discussed.