A non-invasive glucose sensor based on 3D reduced graphene oxide-MXene and AuNPs composite electrode for the detection of saliva glucose

Regular monitoring of blood glucose levels is crucial in diabetes management. Commonly used procedures may be invasive and can lead to cross-infection and inflammation. Therefore, a safe, non-invasive blood glucose-monitoring technology is needed. Herein, a 3D reduced graphene oxide (rGO) electrode was modified with MXene (Ti₃C₂) and gold nanoparticles (AuNPs) to construct a non-invasive, saliva glucose detection electrode. The Au/rGO-Ti₃C₂ electrode exhibited good detection performance for glucose concentrations in the range of 10 µM–21 mM at a working potential of 0.6 V, with a detection limit of 3.1 µM glucose, and a sensitivity of 355 µA mM⁻¹ cm⁻². The Au/rGO-Ti₃C₂ electrode showed almost no response to the addition of interfering substances, and no effect was observed upon subsequent glucose detection. The sensor could detect glucose in artificial saliva and saliva supernatant. The modified electrode showed a significant response to low glucose concentrations, even at 10 µM. These results indicate the suitability of the Au/rGO-Ti₃C₂ electrode for saliva glucose detection. The electrode developed in this study has great potential in improving the efficiency of diabetes monitoring through pain-free, non-invasive glucose detection in saliva.