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-Eu(3+)) complex that could be enhanced by DNA was developed. The GFLX-Eu(3+) 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 × 10(-8) to 1.5 × 10(-6) g mL(-1), with a correlation coefficient (R) of 0.997, and the detection limit (3σ) of the method was determined as 6.0 × 10(-9) g mL(-1). The mechanism of the fluorescence enhancement effect was also discussed.