Application of a new electrochemical sensor based on carbon paste electrode with NiFe2O4 and cross-linked chitosan composite for trace detection of Atorvastatin

In this study, a carbon paste electrode with a composite of NiFe2O4 and cross-linked chitosan (NF@Ch) was used as a simple, rapid and sensitive method with a modified carbon paste electrode (mCPE) for study and determination of Atorvastatin (ATV) content in different samples. At first, the effect of some experimental parameters such as the percent of carbon paste, pH of electrolyte, the scan rate and accumulation time on electrochemical behavior of the drug was independently evaluated and optimized. The electrochemical oxidation mechanism of the drug on the surface of the modified electrode was obtained by the resulted cyclic voltammograms in different scan rates and pHs. In the next step, differential pulse voltammetry was used for detection of atorvastatin in the optimized condition. The response of the mCPE to ATV was found to be linear from 0. 1 nM to 5.0 nM and also from 5.0 nM to 100.0 nM and the sensor had a limit of detection (LOD) of 35 pM. Also, the successful application of the modified electrode in real samples (tablets) was evaluated and appropriate accuracy was obtained

Decorated graphene oxide with gold nanoparticles as a sensitive modified carbon paste electrode for simultaneous determination of tyrosine and uric acid

Abstract It is presented here as a simple, selective, rapid, low-cost, with a wide linear range method to simultaneously determine tyrosine and uric acid using a modified carbon paste electrode decorated with graphene oxide and gold nanoparticles (GO/AuNPs/MCPE). In order to characterize and evaluate the morphology and constituents of the nanostructures, X-ray diffraction spectroscopy, Transmission electron microscopes, Dynamic light scattering, Zeta potential, electrochemical impedance spectroscopy, and Voltammetry were employed. The current response on the surface of the modified electrode had a dynamic linear range relationship in the concentrations of 0.14–340.00 µmol L−1 and 0.06–141.00 µmol L−1 for tyrosine and uric acid, respectively, and the method detection limit (MDL) was 0.0060 µmol L−1 and 0.0037 µmol L−1, respectively. This modified electrode provided high stability, sensitivity, and acceptable reproducibility for voltammetric measurements of tyrosine and uric acid simultaneously in a biological matrix