Highly selective and sensitive detection of β-lactam antibiotics in food samples using a fluorescent turn-on probe based on metal-organic framework

If the functionalized MOF-based fluorescent probes are utilized for detecting structurally related antibiotics, they could achieve breakthrough advancements in recognition efficiency, applicability, and detection scope. Herein, a fluorescence turn-on probe based on a metal-organic framework (MOF), Zn-TBLeuBa, was developed for the first time to detect three β-lactam antibiotics. Zn-TBLeuBa exhibits the significant fluorescence-enhanced response (I/I₀) of 9.1, 8.1, and 5.8 on amoxicillin, amoxicillin sodium, and ampicillin, with a low detection limit of 0.57, 0.45, and 1.7 μmol∙L⁻¹, respectively. The probe was successfully utilized for the trace determination of amoxicillin and ampicillin in cow milk, honey, and pork. Fluorescence lifetime measurements and UV spectroscopy analyses revealed that the surface microenvironment of the framework interacts strongly with antibiotics through hydrogen bonding and π-π stacking. This work established a feasible and promising strategy for the cost-effective, rapid, and highly selective detection of class-specific antibiotics using MOF probes featuring specifically arranged surface functional groups.