Infrared Laser-Induced Graphene Sensor for Tyrosine Detection

In this work, we demonstrate that laser-induced graphene (LIG) electrodes produced by a single-step infrared irradiation on a commercially available polyimide sheet work as portable platforms for the electrochemical detection of tyrosine (Tyr). The LIG surface was characterized by Raman and scanning electron microscopy, which confirmed the formation of graphene with a highly porous structure. The sensor associated with differential-pulse voltammetry provided the determination of Tyr with a linear range between 5 and 30 mu mol L-1, a limit of detection (LOD) of 1.5 mu mol L-1, precision of 6.2 % (n=10), and a satisfying selectivity towards interfering species found in biological media (e. g., dopamine, urea, and both ascorbic and uric acids). Artificial urine samples spiked with different amounts were analyzed by the proposed sensor and recovery values between 107 and 114 % were obtained. Opposite to many works reported in the literature, this platform did not require costly and time-consuming surface modification processes, being an alternative feasible for other applications of clinical/medical interest. One LIG electrode sensor is produced in 140 s without chemical waste generation.