Prussian blue nanocubes on nitrobenzene-functionalized reduced graphene oxide and its application for H2O2 biosensing

• Nitrophenyl groups were spontaneously grafted on RGO by chemical bonding.
• Prussian blue nanocubes monolayer-nitrobenzene-RGO was prepared.
• The electron transfer kinetics in the nanocomposites was investigated.
• Electrocatalytic performances of nanocomposites toward H2O2 were explored.
• The resulted sensor showed good performance for H2O2 detection.

Detection of H2O2 is very important in biological analysis, clinical diagnosis, food industry, etc. This work presents an electrochemical approach for the detection of H2O2 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 H2O2. The resulted H2O2 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 H2O2 under a relatively negative potential. The sensors might be used as a promising one for practical application.

Prussian blue (PB) nanocubes-nitrobenzene-reduced graphene oxide (RGO) nanocomposites (PB nanocubes-nitrobenzene-RGO) 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 nanocomposites modified electrode shows good electrocatalysis toward the reduction of H2O2. Further immobilizing glucose oxidase on the modified electrode, an amperometric glucose biosensor was achieved by monitoring the generated H2O2 under a relatively negative potential. The sensors might be used as a promising one for practical application.Figure optionsDownload as PowerPoint slide