Surface molecularly imprinted polymer capped Mn-doped ZnS quantum dots as a phosphorescent nanosensor for detecting patulin in apple juice

- 6-HNA as dummy template for PAT to create imprinting binding sites.
- Affinity between aminopropyl and PAT responds to phosphorescence quenching.
- Higher specificity for PAT than for its analogues and the dummy template.
- Specific recognition remains with 5-HMF co-existed.
- Recoveries of ∼120% with RSDs of ∼5% for PAT in apple juice.

A Mn-doped ZnS quantum dots (QDs) based nanosensor for selective phosphorescent determination of patulin (PAT) was synthesized with 6-hydroxynicotinic acid (6-HNA) as dummy template via a surface molecular imprinting sol-gel process. FTIR and XRD indicated the successful graft of molecularly imprinted polymer (MIP) onto crystal QDs. Binding tests revealed that the MIP-QDs presented higher selectivity, adsorption capacity and mass transfer rate than non-imprinted polymers, demonstrating a specific recognition for PAT among competitive mycotoxins and its analogues with the imprinting factor of 2.02. The MIP-QDs could recognize PAT in a linear range of 0.43-6.50 μmol L−1 with a detection limit of 0.32 μmol L−1 and a correlation coefficient (R2) of 0.9945. Recoveries of 102.9-127.2% with relative standard deviations <4.95% were achieved in apple juice samples which were in good agreement with high-performance liquid chromatography (HPLC) (P > 0.05). The results indicated a simple phosphorescent nanosensor for PAT detection in complex matrix.