RhB-Functionalized Cd-MOF Composite for Fluorescence Sensing and Anti-counterfeiting.

The development of sensing materials capable of efficiently detecting multiple target analytes remains a core challenge in the field of fluorescence sensing. This work reports a cadmium-based fluorescent metal-organic framework (Cd-MOF), termed CUST-66 (CUST = Changchun University of Science and Technology). CUST-66 exhibits a marked fluorescence "turn-on" response to Hg2+ and enrofloxacin (ENR), while displaying a distinct fluorescence "turn-off" response toward CrO₄2-. On this basis, RhB@CUST-66 was successfully fabricated by incorporating Rhodamine B (RhB) into CUST-66, enabling highly sensitive and selective fluorescence detection of Fe3+, CrO42-, Cr2O72- and tetracycline hydrochloride (HTC). Moreover, to evaluate its practical application potential, fluorescent anti-counterfeiting pens based on RhB@CUST-66 were designed. The RhB@CUST-66-based pen exhibits significantly enhanced fluorescence brightness, enabling visualization of writing and patterns under 365-nm ultraviolet (UV) light. This work can provide new strategies for the accurate detection of target analytes in the environment and for information security and anti-counterfeiting applications.