Spectroelectrochemical and Voltammetric Studies of L‐DOPA

Abstract

AbstractThe electrooxidation of L‐dopa at GC electrode was studied by in situ UV‐vis spectroelectrochemistry (SEC) and cyclic voltammetry. The mechanism of electrooxidation and some reaction parameters were obtained. The results showed that the whole electrooxidation reaction of L‐dopa at glassy carbon (GC) electrode was an irreversible electrochemical process followed by a chemical reaction in neutral solution (EC mechanism). The spectroelectrochemical data were treated by the double logarithm method together with nonlinear regression, from which the formal potential E0=228 mV, the apparent electron‐transfer number of the electrooxidation reaction αn=0.376 (R=0.99, SD=0.26), the standard electrochemical rate constant k0=(3.93±0.12)×10−4 cm s−1 (SD=1.02×10−2), and the formation equilibrium constant of the following chemical reaction kc=(5.38±0.34)×10−1 s−1 (SD=1.02×10−2) were also obtained.