Fluorescence detection for enrofloxacin by using Aptamer and fluorophore SYBR Green I

Abstract

Enrofloxacin (ENR), as a type of antimicrobial, is commonly used in animal sterilization. However, excessive ENR residues in food will seriously harm human health. Therefore, in this work, we developed a quantitative fluorescence method for ENR based on aptamer and SYBR Green I (SG-I). DNA aptamers with G-quadruplex space structure can be recognized and inserted by SG-I to emit intense green fluorescence. In the presence of ENR, the aptamer preferentially recognized and bound specifically to ENR resulting in the change of aptamer conformation, which prevented the SG-I from inserting into the aptamer to cause fluorescence quenching. The aptamer sensor can quantitatively detect ENR with linear concentration range of 0-600 nM, and the limit of detection was 0.158 nM. The aptamer sensor was used detecting ENR in chicken, fish and pork samples with recovery rate from 99.74–104.02%, and relative standard deviation (RSD) of ENR of less than 6%. Therefore, this aptamer-based sensor provided the fluorescence detection method for ENR in food safety.