title: An indirect competitive assay-based aptasensor for detection of oxytetracycline in milk.
abstract: Oxytetracycline (OTC) is a common antibacterial agent used for the control of animal diseases. OTC abuse can seriously affect human health; therefore, we developed a biosensor using single-stranded DNA (ssDNA) aptamers for the detection of OTC. The binding probe aptamers for OTC were selected by a Systematic Evolution of Ligands by the exponential enrichment (SELEX) process and identified by the enzyme-linked aptamer assay (ELAA). Among the selected 5 aptamers, aptamer OTC3 showed the strongest affinity (Kd=4.7 nM) and highest specificity for OTC compared to structurally similar antibiotics, tetracycline and chlortetracycline. OTC was detected using indirect competitive ELAA. The limit of detection and quantitation with aptamer OTC3 were 12.3 and 49.8 µg/L, respectively, in milk and showed recovery rates of more than 90% in OTC-spiked milk. This biosensor method with high sensitivity and specificity based on indirect competitive ELAA can be applied to OTC detection in food products on-site because of the simplicity of detection.
authors.affiliation: Department of Bio Applied Toxicology, Hoseo Toxicology Research Center, Hoseo University, Asan 336-795, South Korea.
authors.forename: Chong-Han
authors.initials: CH
authors.lastname: Kim
authors.forename: Lyun-Pyo
authors.initials: LP
authors.lastname: Lee
authors.forename: Jeong-Ran
authors.initials: JR
authors.lastname: Min
authors.forename: Myung-Woon
authors.initials: MW
authors.lastname: Lim
authors.forename: Sang-Hee
authors.initials: SH
authors.lastname: Jeong
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis*; D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D005504:Food Analysis / Q000379:methods*; D006801:Humans; D057230:Limit of Detection; D008892:Milk / Q000737:chemistry*; D010118:Oxytetracycline / Q000032:analysis*; D052156:SELEX Aptamer Technique
chemical_list: D000900:Anti-Bacterial Agents; D052157:Aptamers, Nucleotide; D010118:Oxytetracycline
keywords: Aptamer; Indirect competitive assay; Oxytetracycline; SELEX; Single-stranded DNA