Ultrasensitive Non-Enzymatic Glucose Sensors Based on Hybrid Reduced Graphene Oxide and Carbonized Silk Fabric Electrodes Decorated with Cu Nanoflowers

The preparation of substrate with high specific surface area and conductivity is very important in the development of non-enzymatic glucose sensors. This study presents a non-enzymatic glucose sensor electrode based on a hybrid reduced graphene oxide (rGO) and carbonized silk fabric (CSF) substrate obtained by immersing silk fabric in a graphene oxide solution and carbonizing at 950 °C in an Ar atmosphere, and then decorating the rGO/CSF surface with Cu nanoflowers by electrodeposition. The optimum Cu-rGO/CSF sensor electrode exhibits high glucose sensitivities of 6613.3 μA mM−1 cm−2 and 1541.7 μA mM−1 cm−2 with linear responses over separate glucose concentration ranges of 0.05–4.0 mM and 4.0–7.0 mM due to the rGO/CSF substrate has high specific surface area, good conductivity and the Cu nanoflowers have high catalytic activity. The electrode also provides a lower limit of detection of 2.27 μM at a signal-to-noise ratio of 3 and high stability in the air. These results demonstrate that the proposed electrode material facilitates the development of simple and accurate non-enzymatic glucose sensors.