Electrochemical Behavior of Vinpocetine at Carbon Paste Electrodes Modified with Calixarenes

Electrochemical behavior of vinpocetine at a plain carbon paste electrode and paste electrodes modified with different calixarenes and ammonium metavanadate was studied by means of cyclic and differential pulse voltammetry. The effect of pH and scan rate on the response at both plain and modified carbon paste electrodes has been revealed. Modification of an electrode with a mixture of ammonium metavanadate and some calixarenes led to considerable decrease of background current along with sensitivity increase as compared to an unmodified carbon paste electrode or an electrode modified with calixarenes only. For the most effective electrode composition, the linear working range was shown to be 2.10−8-6.10−6 M with a detection limit of 5.10−9 M.