One-pot synthesized multifunctional Zn-MOF/HOF heterostructure sensor array assisted by machine learning for...

The ideal multifunctional platform that combines the capabilities of effective capture, sensitive detection, and accurate identification of doxycycline analogs (DCs) remains a serious challenge for ensuring the environment and food security. This work constructs heterostructure Zn-MOF/HOF asynchronous response fluorescence sensor using a multicomponent one-pot method for high-efficiency capturing and sensitive detecting DCs. Metal nodes and functional groups in Zn-MOF/HOF provide sites for specifically recognizing and sensitizing DCs that induce asynchronous response with blue/green fluorescence emission. Fluorescence spectra of Zn-MOF/HOF show characteristic differences due to different spatial conformations and substituents of DCs. Machine learning-assisted Zn-MOF/HOF fluorescent sensing array accurately discriminates DCs with a high precision of 100 %. An exceptional adsorption capacity of DCs up to 569.00 mg/g realizes the effective pre-enrichment of DCs, improving the sensitivity of the Zn-MOF/HOF sensor. The limits of detection of the Zn-MOF/HOF sensor are as ultra-low as 2.2 nmol/L. Satisfactory recoveries of 91.78 %-113.16 % are obtained for detecting DCs in real-world water and food samples. A portable optosmart sensing system integrating the Zn-MOF/HOF sensor and smartphone realizes visual quantitation and on-site monitoring DCs. This work innovatively reveals the great potential of Zn-MOF/HOF heterostructure as a multifunctional platform for simultaneous capture, identification, and sensing of emerging contaminants.