Copper-based two-dimensional metal-organic framework nanosheets as horseradish peroxidase mimics for glucose fluorescence sensing.

Ultrathin two-dimensional (2D) metal-organic framework (MOF) nanosheets have attracted numerous attention due to their unparalleled advantages such as unique structures, large surface areas, good stability and high catalytic efficiency. In this paper, 2D Cu(bpy)(OTf) nanosheets (Cu-MOF, bpy = 4,4-bipyridine, OTf = trifluoromethanesulfonate) are first utilized to achieve the fluorescent detection for HO and glucose with their intrinsic peroxidase-like activity. The fluorescent biosensor Cu-MOF nanosheets were achieved by the efficient catalysis of non-fluorescent thiamine (TH) to strong fluorescent thiochrome in the presence of HO. With the combination of glucose oxidase, highly selective and sensitive fluorescent detection for glucose could be established with a detection limit of 0.41 μM and two separate linear ranges of 10-100 μM and 100-1000 μM, respectively. Furthermore, the developed method has been applied to human serum for the quantitative determination of glucose as a clinical diagnosis indicator of diabetes mellitus.