Amino-Functionalized Luminescent Metal-Organic Framework Test Paper for Rapid and Selective Sensing of SO2 Gas and Its Derivatives by Luminescence Turn-On Effect

Rapid and selective sensing of sulfur dioxide (SO2) gas has attracted more and more attention because SO2 not only causes environmental pollution but also severely affects the health of human beings. Here we report an amino-functionalized luminescent metal organic framework (MOF) material (i.e., MOF-5-NH2) and further investigate its sensing property for SO2 gas and its derivatives as a luminescent probe. The results indicate that the MOF-5-NH2 probe can selectively and sensitively sense SO2 derivatives (i.e., SO32-) in real time by a luminescence turn-on effect with a lower detection limit of 0.168 ppm and a response time of less than 15 s. Importantly, the luminescence turn-on phenomenon can be observed by the naked eye. We also assembled MOF-5-NH2 into a test paper to achieve the aim of portable detection, and the lower-limit concentration of the test paper for sensing SO2 in real time was found to be about 0.05 ppm. Moreover, MOF-5-NH2 also shows good anti-interference ability, strong luminescence stability, and reusability, which means that this material is an excellent sensing candidate. The amino functionalization may also provide a modification strategy to design luminescent sensors for other atmospheric pollutants.