Application of nanosized MCM-41 to fabrication of a nanostructured electrochemical sensor for the simultaneous determination of levodopa and carbidopa

A novel carbon paste electrode modified with nanosized mesoporous MCM-41 was prepared, and used as an electrochemical sensor to study the electro oxidation of levodopa (LD), carbidopa (CD) and their mixtures. Using differential pulse voltammetry (DPV), a highly selective and simultaneous determination of LD and CD has been explored at the modified electrode. The electrochemical sensor displayed a good resolving function for the overlapping voltammetric responses of LD and CD into two separate peaks with a potential difference of 370 mV. DPV peak currents of LD increased linearly with concentration over the 0.13 mu M to 1250.00 mu M range and exhibited a detection limit of 0.072 mu M. Also, the proposed electrochemical sensor was used for the determination of LD and CD in some real samples, using the standard addition method.