A simple, sensitive and reusable bifunctional ratiometric fluorescent sensing platform RhB@Zr-MOF for rapid detection of adenosine triphosphate and malachite green.

A sensitive and accurate ratiometric fluorescent sensor (RhB@UIO-67) is constructed by simply encapsulating rhodamine B (RhB) within a zirconium-based metal-organic framework (UIO-67). Based on the inhibition effect of ligand-to-metal charge transfer, adenosine triphosphate ATP induces a significant enhancement in the MOF centre emission, but does not affect the fluorescence of RhB in the probe material at all, which are respectively employed as detection signal and reference signal to realize sensitive ratiometric fluorescence detection of ATP in human serum and urine with a detection limit (LOD) of 0.45 μM. In particular, since the introduction of the target molecules does not cause any structural degradation, the sensor can be reused. Additionally, due to fluorescence resonance energy transfer between the probe components and malachite green (MG), addition of MG results in different degrees of quenching of the fluorescence emissions of UIO-67 and RhB in the RhB@UIO-67 and thus the probe material can simultaneously serve as a sensitive ratiometric sensing platform for MG detection in aquatic products including fish and shrimp with a low LOD of 0.03 μM. Benefited from its simplicity, sensitivity, and reusability, the sensing material has a wide application potential.