Magnetic capture of sulfur quantum dots encapsulated in MOF-5-NH2 via a target-driven self-cycling catalyzed hairpin assembly for the sensitive detection of patulin

• DOI: 10.1016/j.cej.2021.133624
• Publication Date: 2021-11-16T17:33:39Z
• Authors: Xiaohai Yan; Yuning Zhao; Gengan Du; Qi Guo; Hong Chen; Qian He; Qiannan Zhao; Huanfeng Ye; Jianlong Wang; Yahong Yuan; Tianli Yue
• Keywords: 02 engineering and technology; 0210 nano-technology

Abstract Tools to detect low molecular weight mycotoxin patulin (PAT) are urgently needed because of its harm to human health. Here, we report a simple, effective, and sensitive fluorescent aptasensor based on sulfur quantum dots encapsulated in MOF-5-NH2 (SQDs@MOF-5-NH2) and self-cycling catalyzed hairpin assembly (scCHA) for the detection of PAT in apple juice. The SQDs@MOF-5-NH2 synthesized by a “bottle-around-ship” solvothermal method works as a fluorescent probe and offers enhanced fluorescence intensity and good water-solubility versus MOF-5-NH2 due to the encapsulation of water-soluble SQDs. Meanwhile, the scCHA designed by the two DNA hairpins is initiated after the formation of PAT/aptamer, which further recycles PAT to effectively capture multiple fluorescence probes (SQDs@MOF-5-NH2) and amplify the detection signal. Attributed to the synergistic effect between the strong fluorescence intensity of SQDs@MOF-5-NH2 and the efficient PAT utilization of scCHA, the fluorescent aptasensor exhibits high sensitivity with detection limits as low as 0.753 pg/mL. The system has satisfactory specificity, anti-interference, and reproducibility (RSDs of intra-assay and inter-assay were 3.24% and 8.60%, respectively). The recoveries in apple juice were between 89.03% and 107.67%, which were with good consistency versus high-performance liquid chromatography (HPLC). These data collectively show that the developed fluorescent aptasensor has a good practical application value.