Electrochemical Determination of Valtrex Utilizing Carbon Paste Electrode Modified with Polymeric Film/ZnO Nanoparticles

Valaciclovir (valtrex) is an antiviral drug used in the management of herpes simplex and herpes zoster. Valaciclovir is the l-valyl ester of acyclovir, which is rapidly converted to acyclovir after oral administration by frst-pass metabolism in the liver. Valaciclovir has the same mechanism of action, antiviral spectrum, and resistance profiles as acyclovir with bioavailability [1]. From the electrochemical point of view, only one study has been made on this compound [2]. So the electrochemical determination of the present drug is favorable due to its simplicity, portability, fast responses, good sensitivity and high selectivity. In our present investigation, the poly (L-methionine)/ZnO nanoparticles based electrochemical sensor was fabricated by the electropolymerization of L-methionine on the surface of ZnO nanaoparticles immobilized onto the carbon paste electrode (CPE). The developed electrochemical sensor was abbreviated as poly (L-MeT)/ZnO NPs/CPE. This electrochemical sensor shows an excellent electrochemical activity towards detection of Valacyclovir (VALA). The surface morphology of different modified electrodes was studied by the help of scanning electron microscopy (SEM). The limit of detection (LOD) values for VALA was determined using the differential pulse voltammetry (DPV) with the calculated value of 1.3 µM. The effect of pH, scan rate and concentration of VALA were studied in detail. The presented methodology possesses a reliable reproducibility, repeatability and stability in biological samples. The obtained results suggest that the fabricated composite chemical sensor poly (L-MeT)/ ZnO NPs/ CPE has satisfactory electroanalytical performance. The proposed electrode was successfully applied for VALA determination in pharmaceutical formulations with promising results.