Mohamad Ali Zare - Young Researchers and Elite Club, Marvdasht Branch, Islamic Azad University, Marvdasht, Iran
Omran Moradlou - Department of Chemistry, College of Sciences, Alzahra University, Tehran, Iran
Behjat Tahmasebi - Young Researchers and Elite Club, Marvdasht Branch, Islamic Azad University, Marvdasht, Iran.
Maryam Iranpour - Department of Chemistry, Shiraz Branch, Islamic Azad University, Shiraz, Iran
Parisa Farashi - Young Researchers and Elite Club, Marvdasht Branch, Islamic Azad University, Marvdasht, Iran.

The electrochemical behavior of captopril at the surface of a carbon-paste electrode (CPE) modified with gold nanoparticles (GNPs) is described. The prepared electrode shows an excellent electrocatalytic activity toward the oxidation of captopril, which is leading to marked considerable improvement of sensitivity. Whereas at the surface of unmodified electrode an electrochemical activity for captopril cannot be observed, a very sharp anodic wave with an anodic peak potential about ۱.۰V (versus Ag/AgCl) is obtained using the prepared modified electrode. Captopril oxidation on CPE/GNPs proceeds at pH between ۴.۰ and ۱۰.۰. Under the optimized conditions, the electrocatalytic oxidation peak current of captopril showed two linear dynamic ranges with a detection limit of ۸.۲۸×۱۰-۲ µM captopril. The linear calibration range was ۱.۱۴-۱۶.۹۸ and ۲۱.۴۹-۶۲.۱ µM using amperometric. Finally, the sensor was examined as a selective, simple, and precise new electrochemical sensor for the determination of captopril in pharmaceutical samples including tablets and satisfactory results were obtained.

Electrochemical, Determination, Captopril, Gold Nanoparticle