Aptamer-Based Fluorescent Switch for Sensitive Detection of Oxytetracycline

Oxytetracycline (OTC) is one of the most used antibiotics in veterinary medicine. There is a large concern about developing antibiotic resistance in humans as a result of the consumption of products contaminated with OTC, so a fast detection technique for an on-field screening test is highly in demand. Here we introduce a novel aptasensor for fast detection of OTC, based on a triple helix molecular switch (THMS) complex formation. The limit of detection (LOD) of this sensor was 1.67 and 6.44 nM in phosphate buffer and milk samples, respectively. Moreover, the sensor showed a high selectivity towards OTC.