Ultra-sensitive molecularly imprinted electrochemical sensor for patulin detection based on a novel assembling strategy using Au@Cu-MOF/N-GQDs

[Display omitted] •A novel molecularly imprinted sensor strategy for the ultrasensitive detection of patulin is constructed.•Integrating N-GQDs/Au@Cu-MOF with molecularly imprinted polymers exhibit distinct synergic effect.•The sensor showed excellent patulin sensing performance in apple juice samples compared to chromatographic methods. This study introduces an innovative procedure for the development of a molecularly imprinted electrochemical sensor for ultra-sensitive and selective detection of patulin. Firstly, the surface of a glassy carbon electrode (GCE) was decorated by nitrogen doped graphene quantum dots (N-GQDs) and AuNPs-functionalized Cu-metal organic framework (Au@Cu-MOF) and then a layer of molecularly imprinted polymer (MIP) was grown on Au@Cu-MOF/N-GQDs/GCE by electropolymerization. Electrochemical techniques were used to characterize and study the electrochemical behavior of the MIP/Au@Cu-MOF/N-GQDs/GCE, which exhibited a stable reference peak of Au@Cu-MOF at −0.11 V after elution of patulin molecules. This peak current density decreased with rebinding of patulin molecules therefore it was considered as indicator signal. The designed MIP sensor presented a wide linear range from 0.001 to 70.0 ng mL−1, and a low detection limit (0.0007 ng mL−1). This newly developed method based on the synergistic effects of N-GQDs and Au@Cu-MOF combined with MIP technique offered outstanding selectivity, sensitivity, stability, and reproducibility. The good accuracy (recovery%, 97.6–99.4) and high precision (RSD%, 1.23–4.61) of this sensing system for analysis of apple juices proved the high potential of it for rapid and low cost determination of patulin compared to chromatographic methods.