Luminescent MOF nanosheets for enzyme assisted detection of H2O2 and glucose and activity assay of glucose oxidase

2D metal-organic framework (MOF) nanosheets have emerged as a novel kind of sensing materials due to the large external surface area and accessible active sites on the surface. In this work, we successfully prepared luminescent MOF nanosheets (In-aip) with thickness of 4 nm by the cation-exchange mediated sonication of a 2D connected anionic MOF. Using In-aip as fluorescent sensor, an enzyme assisted system was established for the analysis of H2O2 with the quenching effect of the oxidation product on its emission. The nanosheet morphology of In-aip ensures its high capture efficiency of unstable intermediate, so high sensitivity was achieved (detection limit = 0.87 mu M). With high sensitivity and wide quantitative range, this H2O2 sensing system could be used as a universal platform for the analysis of H2O2 related biomolecules and enzymes. By multi-enzyme cascade catalysis, a detection method of glucose and an activity assay of glucose oxidase were developed based on it. This work is the first example of using luminescent MOF nanosheets to bioanalysis and shows their wide application potential.