Novel electrochemical sensing platform for caffeine using three dimensional NiO nanowrinkles modified glassy carbon electrode

We addressed electrochemical behaviors of caffeine at the modified sensor (three dimensional NiO nanowrinkles modified glassy carbon electrode (3D NiO NWs/GCE)) in an aqueous medium with cyclic voltammetry, differential pulse voltammetry and chronoamperometry. The modification of sensor was performed by drop-casting process. Electrochemical investigations showed that the fabricated 3D NiO NWs/GCE sensor exhibited excellent catalytic performance for the oxidation of caffeine. Based on the optimal conditions of pH=7.0 in CV, caffeine oxidation happens at a potential ~200 mV less positive than that of the unmodified GCE. The current response of 3D NiO NWs/GCE sensors presents a remarkable sensitivity based on CV. The calibration plot is linear (R²: 0.9991) over the concentrations ranging between 0.1 and 800.0 μM of caffeine. Limit of detection (LOD) was 0.03 μM for caffeine.