Defect-Engineered Zr-TCPE Coupled with a Target-Oligonucleotide-Driven DNAzyme Motor for Ultrasensitive Patulin Detection in Apple Juice

Patulin (PAT) is a mycotoxin with immunotoxicity, genotoxicity, and neurotoxicity, so effective methods are needed for its detection. Fluorescence aptasensors provide a homogeneous detection method, but their sensitivity needs to be further improved. Herein, we developed a fluorescence aptasensor based on a target-oligonucleotide-driven DNAzyme motor and defective Zr-TCPE for PAT detection. The defective Zr-TCPE achieved an enhanced fluorescence intensity (increased by ∼1.9-fold) via defect engineering. The target-oligonucleotide-driven DNAzyme motor achieved effective PAT transduction, with a signal background ratio 4.4-fold that of the competitive transduction strategy. By combining defective Zr-TCPE with a target-oligonucleotide-driven DNAzyme motor, we achieved ultrasensitive detection of PAT with a detection limit as low as 9.38 fg/mL. In addition, the proposed fluorescence aptasensor could be used for the detection of PAT in apple juice, with recoveries ranging from 95.93% to 105.71%. This fluorescence aptasensor provides reasonable guidance for trace detection of hazardous substances in food and the environment.