Screen-Printing Preparation of High-Performance Nonenzymatic Glucose Sensors Based on Co₃O₄ Nanoparticles-Embedded N-Doped Laser-Induced Graphene

Precise acquisition of the blood glucose level is one of the most critical indicators for the prevention and treatment of diabetes. Compared with the high cost and instability of enzyme-based glucose sensors, the development of low-cost, high-sensitivity, and fast-response nonenzymatic glucose sensors is imperative. Herein, bulk Co3O4-embedded N-doped laser-induced graphene (Co3O4@NLIG) powder is in situ fabricated through a high-efficiency and simple laser-scribing technique and successfully made into a screen-printing paste for screen-printed electrodes (SPEs), followed by use as an enzyme-free glucose sensor. The electrocatalytic results show that the as-prepared Co3O4@NLIG/SPE glucose sensor has a high sensitivity of 143 μA mM–1 cm–2, a broad linear detection range of 1 μM to 11 mM, an ultralow detection limit of 0.48 μM, and a rapid response time of <1 s. The as-prepared sensor also has prominent reproducibility, stability, and immunity to interference. Furthermore, the glucose-sensing mechanism of the sensor is profoundly explored. Such an outstanding electrocatalytic performance endows the Co3O4@NLIG/SPE nonenzymatic glucose sensor with potential applications in blood glucose monitoring and diagnosis.