Sustainable Laser-Induced Graphene Electrochemical Sensors from Natural Cork for Sensitive Tyrosine Detection

Cork laser induced graphene (cork-LIG) electrochemical sensors are fabricated by direct laser writing of natural cork sheets. Laser writing is performed with a hobbyist visible laser. The obtained cork-LIG structures display graphene-like Raman signatures, high conductivity, and fast electron-transfer rates. After a 10 min electrochemical pretreatment, electrodes are used for detection of Tyrosine (Tyr) in the presence of uric acid, dopamine, ascorbic acid, urea, and glucose. linear detection of tyrosine is achieved in the 5–150 µm range with a limit of detection (LOD) of 3.03 µm. Calibration of dopamine detection is achieved with a LOD of 1.1 µm. Finally, the cork-LIG electrochemical sensors show linear response of Tyr in artificial sweat in the relevant physiological range of 5–250 μm (sensitivity, 1.8×10⁻² A m⁻¹). The LOD is calculated as 3.75 μm. These results open the door to the exploitation of renewable materials such as cork for the development of high-quality, green sensors for the monitoring of health and wellbeing parameters.