Development of a high-performance Cu–Ni decorated laser-induced graphene sensor for nonenzymatic glucose monitoring in sweat

Biosensors and accurate monitoring of glucose levels play a crucial role in the diagnosis and management of chronic metabolic disorders such as diabetes mellitus. Pertaining to the need of developing a sensitive noninvasive glucose detection system, the aim of this study was to design and fabricate a high-performance nonenzymatic, rapid and affordable glucose monitoring device. To reach that aim, porous Ni–Cu nanosheets were electrodeposited on 3D laser-induced graphene sheet. The Ni–Cu coatings were fabricated using electrolytic bath using different Cu²⁺:Ni²⁺ concentration ratios. The developed biosensors were characterized by SEM complemented with EDS, XPS, cyclic voltammetry, EIS and chronoamperometry characterizations techniques. The efficiency of the fabricated electrodes as a wearable biosensor was tested through glucose detection in artificial sweat as a biological fluid that can be used in real-time monitoring. The results revealed excellent sensor analytical performance through exhibiting a wide linear range with a significantly high sensitivity (11,012.73–15,286.66 μA/mM.cm²) and low detection limit (0.0062 μM). The sensor also demonstrated a stable selective response with the presence of interfering compounds. The Ni-Cu-LIG sensor was able to detect the glucose in artificial sweat samples, and hence, they show a great potential to be used as a real-time wearable device.