Ultrasensitive ciprofloxacin assay based on the use of a fluorescently labeled aptamer and a nanocomposite prepared from carbon nanotubes and MoSe2

摘要

A nanocomposite was prepared from carbon nanotubes and MoSe2 (CNT-MoSe2). This nanomaterial quenches the fluorescence of fluorescein-labeled aptamers. When ciprofloxacin (CIP) binds to the aptamer, an aptamer/G-quadruplex complex will be formed and the interaction between labeled aptamer and CNT-MoSe2 nanostructures is weakened. This leads to significant fluorescence recovery. Under optimized experimental conditions, the limit of detection is 0.63ngmL(-1) with a good linearity in the range from 0.63 to 80ngmL(-1). The assay was applied to the determination of CIP in spiked milk, and the recoveries range between 94.3 and 97.0% (n=3). Conceivably, the method is a generic approach that can be extended to the determination of other analyte for which adequate aptamers are available.