Prussian blue nanocubes on nitrobenzene-functionalized reduced graphene oxide and its application for H_2O_2 biosensing

摘要

Detection of H_2O_2 is very important in biological analysis, clinical diagnosis, food industry, etc. This work presents an electrochemical approach for the detection of H_2O_2 based on Prussian blue (PB) nanocubes-nitrobenzene-reduced graphene oxide (RGO) nanocomposites (PB nanocubes-nitrobenzene-RGO). The hybrid nanocomposites were constructed by growing PB nanocubes onto the nitrobenzene-RGO composites which were prepared by spontaneous grafting nitrophenyl groups to the basal carbon atoms of RGO based on chemical bonding. The obtained PB nanocubes-nitrobenzene-RGO nanocomposites were characterized by scanning electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy. The formation mechanism of PB nanocubes-nitrobenzene-RGO nanocomposites was investigated and discussed in detail. The PB nanocubes-nitrobenzene-RGO modified glassy carbon electrode shows good electrocatalysis toward the reduction of H_2O_2. The resulted H_2O_2 biosensor exhibited a rapid response of 2 s, a low detection limit of 0.4 μM, a wide linear range of 1.2 μM to 15.25 mM and high sensitivity of 300.16 μA cm~(-2) mM~(-1), as well as good stability, repeatability and selectivity. Further immobilizing glucose oxidase on the PB nanocubes-nitrobenzene-RGO nanocomposites/GCE, an amperometric glucose biosensor was achieved by monitoring the generated H_2O_2 under a relatively negative potential. The sensors might be used as a promising one for practical application.