Synthesis of chitosan-Prussian blue-graphene composite nanosheets for electrochemical detection of glucose based on pseudobienzyme channeling

The chitosan-Prussian blue-graphene (CS-PB-GR) composite nanosheets were prepared and a glucose biosensor was developed based on the composite nanosheets and sugar-lectin biospecific interactions. In such systems, PB could couple with glucose oxidase (GOD) to form pseudobienzymatic systems. The composite nanosheets not only provide GR such a remarkable electrical conductivity with PB as a redox probe, but also offer an interface of abundant amino-groups to assemble nanoparticles for the first layer GOD. The second layer of GOD was immobilized onto the electrode by the excellent biological affinity links between Con A and sugar chains intrinsically. The biosensor exhibits good electrocatalytic behavior to detection of glucose at an applied potential of −0.2 V and the linear response range from 2.5 × 10−5 to 3.2 × 10−3 M with a correlation coefficient of 0.9979 and the detection limit of 1.0 × 10−5 M at the signal-to-noise ratio of 3. Some important parameters of the sensor were evaluated and discussed in detail.