Fluorescent Aptasensor for Enrofloxacin Detection based on APE1 Assisted Amplification and CsPbBr 3 @MSN Nanocomposites

Abstract

In this work, a fluorescent aptasensor was constructed for enrofloxacin (ENR) detection by combining with the polyvalent aptamers (PAs) structure, apurinic/apyrimidinic endonuclease 1 (APE1) mediated signal amplification and mesoporous silica encapsulated perovskite quantum dots (CsPbBr3@MSN) nanocomposites. With multiple recognition sites, polyvalent aptamers bond with ENR and released the trigger for strand displacement reaction. Meanwhile, a highly sensitive FRET based sensor was constructed by using CsPbBr3@MSN probe and gold nanoparticles (Au NPs). In the presence of trigger and APE1, the fluoresence was recovered by separating the CsPbBr3@MSN probe and Au NPs with a cyclic strand displacement reaction. Coupling with the signal amplification strategy, this system achieved linear detection of ENR in the range of 0.1 pg/mL to 50 ng/mL with a detection limit of 0.073 pg/mL. This sensor offers a novel analytical strategy for detecting antibiotic residues and holds significant potential for applications in food safety monitoring and environmental analysis.