Target-activated dual-amplified photothermal aptasensing platform for highly sensitive monitoring antibiotic residue in foods

Antibiotic residues have attracted increasing public attention in food safety because extensive use or misuse of antibiotics seriously threatens public health and safety. Thus, it is important to develop accurate and sensitive analytical methods for the detection of residual antibiotics in foods. Herein, we developed a novel, reliable and highly sensitive photothermal aptasensing platform for analysis of antibiotic residue in food samples. By virtue of CuS/cyanine dye nanocomposite as an excellent photothermal conversion reagent, and dual amplification strategy consisting of exonuclease I-aided target recycling and hybridization chain reaction, highly sensitive detection of antibiotic, i.e. chloramphenicol (CAP), was successfully realized with a detection limit as low as 2.8 pM, which was superior to most of the reported methods for CAP determination. In addition, the as-proposed dual-amplified photothermal aptasensing platform was highly applicable for monitoring antibiotic residue in various food samples with good accuracy and repeatability. More importantly, this work was the first constructed photothermal aptasensing platform for antibiotic detection. Therefore, with the excellent features of simplicity, portability, wide availability, and easy manipulation, this sensing platform has great potential to be applied in antibiotic-related food safety monitoring.