Cu-MOF@Pt 3D nanocomposites prepared by one-step wrapping method with peroxidase-like activity for colorimetric detection of glucose.

As an alternative to natural enzymes, artificial enzymes based on nanomaterials have attracted a lot of attention owing to their outstanding catalytic activity and high stability as well as low cost. Cu-MOF loaded with platinum nanoparticles (labeled Cu-MOF@Pt) was prepared by simple one-step wrapping method using platinum nanoparticles, copper nitrate trihydrate and 1,3,5-tricarboxybenzene. It was confirmed that Cu-MOF@Pt exhibits peroxidase-like activity, which can quickly catalyze the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) and produce blue oxidized TMB (oxTMB) in the presence of hydrogen peroxide (HO). Additionally, steady-state kinetics showed that Cu-MOF@Pt exhibits stronger appetency to TMB and HO compared with horseradish peroxidase. Thanks to the peroxidase-like activity of Cu-MOF@Pt, a highly selective colorimetric method for glucose detection has been successfully established, the linear range is 2-15 mM (R =0.9999) and the Limit of Detection (LOD) is 0.42 mM, with a detection range that meets clinical needs. Moreover, its good intra- and inter-assay precision and excellent stability make the results of glucose detection very reproducible. The detection performance of 90.09% was still maintained at 4 ℃ for 2 months. In conclusion, a new nanocomposite was successfully prepared and its selective detection ability for glucose was proved, which established a good basis for the clinical development of new enzymes for biosensors.