Covalent organic frameworks-based SERS aptasensor for ultrasensitive and specific detection of patulin in apples

Patulin (PAT), a hazardous mycotoxin prevalent in apples, poses significant food safety risks requiring sensitive detection methods.In this work, a SERS aptasensor utilizing covalent organic frameworks (COFs) anchored with silver nanoparticles (AgNPs) was designed, which is capable of specifically detecting PAT in the presence of interfering substances in apple matrices. Consequently, the Raman signal intensity exhibits an inverse relationship with the concentration of PAT. The method demonstrates high sensitivity and stability, with a linear detection range of 0.1–250 ng/mL and a limit of detection of 0.0544 ng/mL. The developed aptasensor shows excellent potential for rapid, on-site PAT screening in food industry quality control, with performance exceeding regulatory requirements. This work also contributes to the application of COFs in SERS technology.