Electrochemical determination of clozapine on MWCNTs/new coccine doped PPY modified GCE: an experimental design approach.

The electrooxidation of clozapine (CLZ) was studied on the surface of a glassy carbon electrode (GCE) modified with a thin film of multiwalled carbon nanotubes (MWCNTs)/new coccine (NC) doped polypyrrole (PPY) by using linear sweep voltammetry (LSV). The pH of the supporting electrolyte (D), drop size of the cast MWCNTs suspension (E) and accumulation time of CLZ on the surface of modified electrode (F) was considered as effective experimental factors and the oxidation peak current of CLZ was selected as the response. By using factorial-based response-surface methodology, the optimum values of factors were obtained as 5.44, 10 μL and 300 s for D, E and F respectively. Under the optimized conditions, a significant increase (~14 times) was observed in the anodic peak current of CLZ on the surface of the modified electrode relative to the bare GCE. Oxidation peak currents increased linearly with CLZ concentration in the range of 0.01-5.00 μM with a detection limit of 3.00 nM. The RSD value for the peak current of CLZ was obtained as 4.5%. The modified electrode with high sensitivity, stability and good reproducibility was used for the determination of CLZ concentration in pharmaceutical and clinical preparations with satisfactory results.