Electrocatalytic Oxidation of Calcium Folinate on Carboxyl Graphene Modified CuxO/Cu Electrode

Carboxyl graphene modified CuxO/Cu electrode was fabricated. The bare copper electrode was firstly anodic polarized in 1.0 mol/L NaOH solution in order to get CuxO nanoparticles, then the carboxyl graphene (CG) was electrodeposited on the CuxO/Cu electrode by cyclic potential sweeping. The electrocatalytic oxidation behaviors of calcium folinate (CF) at the graphene modified CuxO/Cu electrode were investigated by cyclic voltammetry. A positive scan polarization reverse catalytic voltammetry was used to obtain the pure catalytic oxidation current. The graphene modified CuxO/Cu electrode was served as the electrochemical sensor of CF, a highly sensitivity of 22.0 µA·(µmol/µL)−1cm−2 was achieved, and the current response was linear with increasing CF concentration in the range of 2.0×10−7 mol/L to 2.0×10−5 mol/L, which crossed three orders of magnitude, and the detection limit was found 7.6×10−8 mol/L (S/N=3). In addition, the proposed sensor was successfully applied in determination of CF in drug sample.