The fabrication of fluconazole-sensitive electrochemical sensor with electrode modification

Fluconazole is an orally administered triazole derivative, an antifungal drug active ingredient. This study aims to make an electrode sensitive to Fluconazole (Fluk) and coated with a molecularly imprinted polymer (MIP). For this purpose, a 0.7 mm pencil tip (PGE) was selected as the working electrode and activated by chemical and electrochemical methods to increase its sensitivity. MIP electrodes were prepared by bare PGE and activated PGEs in the presence of 20 mM ortho-phenylenediamine (o-PD) and 5.70 mM Fluconazole in a 0.5 M H2SO4 solution. Deposition of MIPs was conducted 9, 18, and 27 cycles in the range of (-0.4 V) to (+1.3V) volts by cyclic voltammetry (CV) technique. The activation of the PGE electrode results in an anodic-cathodic peak separation decrease and an increase in the peak current of the standard redox couple. As the number of CV cycles increased, the electrical conductivity of MIP decreased. Each step was followed by electrochemical impedance spectroscopy (EIS). Activated in ethanol-HCl medium and MIP electrodes prepared with 9 and 18 cycles were linearly sensitive to the analyte concentration in the range of 1x10-13-1x10-5 M. MIP performance in BR buffer at different pH was investigated. It was concluded that it performed better at pH=6.0.