Abstract: Abstract: Enrofloxacin, as a fluoroquinolone antibacterial agent, has been widely used to treat the infections of animal tissues. Only a weak fluorescence can be provided when AccuBlue fluorescent dyes are free or coexist with single-stranded DNA, whereas the fluorescent signals can be significantly enhanced when AccuBlue fluorescent dyes coexist with double-stranded DNA. In this study, a novel fluorescence detection method for enrofloxacin was established based on the reaction between AccuBlue fluorescent dyes and a nucleic acid aptamer. The optimal detection conditions were as follows: buffer solution with pH 8.5, incubation of the double strand for 10 min, and time for the fluorescent dye to recognize the double strand was 6 min. Results indicate that calibration curves were linear in the range of 20-1000μg/L. Validation of the method yielded a limit of detection (S/N ≥ 3) of 9.96μg/L. The intra- and inter-plate variation coefficients were in ranges of 4.97%-9.31% and 5.83%-10.96%, respectively. Recoveries measured for the extraction of enrofloxacin spikes into milk powder, shrimp and beef were between 76.54% and 98.79%. The method developed is specific, stable, reproducible, and could be easily implemented for rapid detection of enrofloxacin in other samples.

Key words: Key words: Enrofloxacin, Aptamer, Fluorescent dye, Rapid detection