Rapid Fluorometric Screening of Antibiotics in Seafood

Simple and rapid fluorometric screening methods have been developed based on the competitive binding between the target and an intercalating fluorophore dye to double-stranded-DNA (dsDNA). In this study, the long-wavelength fluorescente dye TOTO-3 was employed as the indicator. Compounds that interact with dsDNA will affect the binding of TOTO-3 to the nucleic acid thereby changing the fluorescence intensity. The analyte concentration is indirectly determined by the decrease in fluorescence intensity. A fiber optic fluorescence screening system was developed for rapid and convenient sample processing. Lambda DNA (48.5 kb) was chosen as a suitable sensing nucleic acid material. Detection of sulfathiazole and chloramphenicol in shrimps using this method was studied in the range of 0.5–25 ng mL⁻¹ of sulfathiazole and of 1–50 ng mL⁻¹ of chloramphenicol. Detection limits of 0.5 ng mL⁻¹ of sulfathiazole and 1 ng mL⁻¹ of chloramphenicol were achieved. This approach is useful as a routine test in the monitoring of antibiotics in the environment or aquaculture products. The easy operation and the rapid and sensitive detection make this a potential high-throughput screening method.