L-Lysine modified glassy carbon electrode for the detection of dopamine in the presence of ascorbic acid

A covalent modified glassy carbon electrode with L-Lysine (Lys/GCE) has been fabricated via an electrochemical oxidation procedure. It is used to electrochemically detect dopamine (DA) and ascorbic acid (AA). The results indicated that L-Lysine monolayer on the surface of glassy carbon electrode (GCE) not only can improve the electrochemical behaviors of DA and AA, but also can resolve the mixed voltammetric response of DA and AA at GCE into two well-defined voltammetric peaks. The separation between the two peak potentials were about 507mV in cyclic voltammetry (CV) and 460mV in differential pulse voltammetry (DPV), respectively, which were large enough for the determination of DA in the presence of AA.