Renewable Surface Carbon-composite Electrode Bulk Modified with GQD-RuCl3 Nano-composite for High Sensitive Detection of L-tyrosine

The ability to analytically detect L-tyrosine is a clinical necessity not only for the diagnosis of some diseases such as tyrosinemia, but also for the study on various tyrosine-associated disorders. In here, graphene quantum dot (GQD) was synthesized by carbonization of citric acid and used to prepare GQD-RuCl3 nano-composite. GQD and GQD-RuCl3 were characterized by Fourier transform infrared (FTIR) and Transmission electron microscopy (TEM). Next the nano-composite was modified with carbon-composite electrode (CCE) and the electrochemical properties of GQD-RuCl3 jCCE were studied by cyclic voltammetry (CV). This bulk modified electrode showed good electrocatalytic activity for L-tyrosine oxidation. The values of the detection limit and sensitivity were obtained as 0.23 mM and 90 nA/mM. The results indicated that the synergistic incorporation of RuCl3 with GQD conspicuously promotes the sensitivity of the sensor. Moreover, the sensor showed long-term stability and good selectivity towards the detection of L-tyrosine.