Enzyme-chitosan hydrogels for high sensitivity flexible silk-based electrochemical glucose sensor

Developing enzymatic glucose sensors with high stability and excellent sensing performance is beneficial for the diagnosis and real-time monitoring of diabetes. In this study, we developed an enzymatic glucose sensor with the RGO (Reduced Graphene Oxide) /SF (Silk Fibroin) composite membrane as a flexible and conductive substrate, and then PB (Prussian Blue) was deposited on the surface of RGO/SF. To enhance the stability of GOD (Glucose Oxidase) and enzymatic glucose sensor, enzyme-chitosan hydrogel electropolymerized on the PB/RGO/SF electrode surface and at last a Nafion layer was coated on the hydrogel to prevent hydrogel detachment and mitigate the effects of interferent. This developed GOD/PB/RGO/SF sensor exhibits good sensing performance in glucose detection, with a response time of less than 10 s, a sensitivity as high as 230.96 μA mM−1 cm−2 at low concentration, and a linear range of 65.57 μM–10 mM, and it also shows good anti-interference feature and reproducibility, providing the reliable sensing performance for detecting glucose levels in human organisms and drinks. In conclusion, the GOD/PB/RGO/SF flexible sensor developed in this study has good prospects for application in glucose real-time monitoring and flexible sensing device.