A Dual-Functional Lanthanide-Doped Ce-MOF Probe for Dual-Recognition Detection of Listeria monocytogenes

Foodborne Listeria monocytogenes ( L. monocytogenes ) poses a serious threat to public health, yet conventional detection methods remain time-consuming and lack sufficient sensitivity for complex food matrices. To address this gap, a Tb 3+ -doped mixed-valence cerium-based metal–organic framework (Tb 3+ @MVCM) was developed as a dual-functional probe via in situ partial oxidation of cerium-based metal–organic frameworks (Ce-MOFs) followed by Tb 3+ doping. This probe exhibits both fluorescence emission and redox activity. Based on this, we designed a dual-recognition, dual-mode aptasensor combining the Gram-positive bacteria binding capability of vancomycin (Van) with the specific molecular recognition of nucleic acid aptamers (Apt). The fluorescence signal of the Apt/Tb 3+ @MVCM–Van/Fe 3 O 4 –L. monocytogenes complex enabled highly sensitive detection with a limit of detection (LOD) of 5.19 CFU/mL, while the residual probe catalyzed a colorimetric reaction yielding an LOD of 6.48 CFU/mL. The analytical performance of this strategy was further validated using real tap water and milk samples, each spiked at three concentration levels. The obtained recoveries ranged from 92.3% to 109%, with relative standard deviations below 5.76%, confirming its applicability for real sample analysis. Overall, this study presents an innovative approach for the rapid detection of L. monocytogenes , and provides a convenient tool for food safety monitoring.