Cu-hemin metal-organic frameworks with peroxidase-like activity as peroxidase mimics for colorimetric sensing of glucose

In this work, a facile strategy to synthesize Cu-hemin metal-organic frameworks (MOFs) with peroxidase-like activity was reported. The prepared Cu-hemin MOFs were characterized by various techniques such as scanning electron microscopy, transmission electron microscopy, X-ray powder diffraction, Fourier transform infrared spectroscopy, UV-visible absorbance spectra, and so on. The results showed that the prepared Cu-hemin MOFs looked like a ball-flower with an average diameter of 10 mu m and provided a large specific surface area. The Cu-hemin MOFs possessing peroxidase-like activity could be used to catalyze the peroxidase substrate of 3,3,5,5-tetramethylbenzidine in the presence of H2O2, which was employed to detect H2O2 quantitatively with the linear range from 1.0 mu M to 1.0 mM and the detection limit was 0.42 mu M. Furthermore, with the additional help of glucose oxidase, a sensitive and selective method to detect glucose was developed by using the Cu-hemin MOFs as catalyst and the linear range was from 10.0 mu M to 3.0 mM and the detection limit was 6.9 mu M. This work informs researchers of the advantages of MOFs for preparing biomimetic catalysts and extends the functionality of MOFs for biosensor application.