Functionalized graphene quantum dots based non-enzymatic sensor for selective tyrosine detection

Tyrosinemia is an inherited metabolic disorder that occurs due to the disruption in the breakdown of the amino acid 'tyrosine'. Elevated levels of tyrosine cause liver failure, and neurological damage in newborns. Hence, rapid and accurate detection of tyrosine is essential for the timely management and diagnosis of this disorder. In this context, a non-enzymatic electrochemical sensor has been fabricated using Graphene Quantum Dots (GQDs) functionalized screen-printed carbon electrode for the detection of tyrosine. The different functional groups present on the surface provides efficient binding and recognition of tyrosine. The electrochemical signatures of the fabricated electrodes exhibited a sensitivity of 0.03 µA µM^-1, detection limit of 0.102 µM, linear range of 5-60 µM, and quantification limit of 0.3094 µM. The selective nature of the sensor was confirmed in the presence of possible interfering amino acid species and the promising figure of merits may be tested to detect tyrosine in clinical samples.