Development of Rapid and Label-Free Fluorescence Sensing of Tetracyclines in Milk Based on Poly(Adenine) DNA-Templated Au Nanoclusters

In this work, a rapid and label-free fluorescent sensing method has been established for tetracycline (TC) detection by using poly(adenine) (poly A) DNA-templated Au nanoclusters (AuNCs) as fluorescence indicator. The obtained AuNCs exhibited excellent fluorescence intensity and good stability. In the presence of tetracycline, the fluorescence intensity of AuNCs was obviously reduced due to the interactions between the tetracycline and the poly A DNA-templated AuNCs. Under the optimum conditions, the strategy permitted sensitive detection of tetracycline in a linear range from 0.1 to 60 μM and with a limit of detection of 20 nM. In addition, the sensor was successfully applied to determinate the tetracycline content in milk samples. More importantly, it could be easily performed within 10 min at room temperature. Thus, it could provide a rapid, convenient, label-free, and high-sensitive fluorescent platform for tetracycline detection.