in vitro selection of rna aptamers that selectively bind danofloxacin danofloxacin is a synthetic fluoroquinolone with broad spectrum antibacterial activity that is used for the treatment of respiratory diseases in animal husbandry however danofloxacin has many adverse reactions and is toxic to humans especially it detrimentally affects muscle central nerve system peripheral nerve system liver and skin in those who ingest foods in which danofloxacin has accumulated prescreening and determination of the level of danofloxacin in foods or food products is necessary for human health aptamers are composing of oligonucleotides that specifically interact with target molecules they are emerging as detectiondiagnostic ligands here we used the selex in vitro selection technology to identify specific and highaffinity rna aptamers with 2fluoro2deoxyribonucleotide modified pyrimidine nucleotides against danofloxacin selected rna aptamers bound specifically to danofloxacin but not to tetracycline truncation of rna aptamer up to 36 mer did not comprise specificity and affinity the truncated rna aptamer specifically bound to target chemical allowing the discrimination of danofloxacin from other fluoroquinolones the isolated specific aptamer could be a potential agent used for the rapid and costeffective detection and sensing of danofloxacin replacing instrumental methods including the more expensive and timeconsuming methods of high performance liquid chromatography and liquid chromatographymass spectrometry