Electrochemical Oxidation and Determination of Antiviral Drug Acyclovir by Modified Carbon Paste Electrode With Magnetic CdO Nanoparticles

With the development of nanomaterials in electrochemical sensors, the use of nanostructures to modify the electrode surface has been shown to improve the kinetics of the electron transfer process. In this study, a sensor was developed for the electrochemical determination of Acyclovir (ACV) based on the modified carbon paste electrode (CPE) by CdO/Fe3O4. The magnetic CdO nanoparticles characterization was studied by energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). To study of the modified CPE surface morphology, scanning electron microscopy (SEM) was used. At the optimal conditions, a noteworthy enhancement in the electrochemical behavior of ACV was observed at the surface of the modified CPE compared to the unmodified CPE. A detection limit of 300 nM and a linear range of 1�100 μM were obtained for the quantitative monitoring of ACV at the modified CPE surface using differential pulse voltammetry (DPV) in phosphate buffer. The RSD (relative standard deviation) of the electrode response was <4.3 indicating the development of a high precision method. Also, satisfactory results were obtained in the determination of ACV with the modified electrode in tablet, blood serum, and urine samples with a satisfactory relative recovery (RR) in the range of 94.0�104.4. © Copyright © 2020 Naghian, Marzi Khosrowshahi, Sohouli, Pazoki-Toroudi, Sobhani-Nasab, Rahimi-Nasrabadi and Ahmadi

Fabrication of an electrochemical mesalazine sensor based on ZIF-67

This paper describes the application of ZIF-67 nanoparticles for carbon paste electrode (CPE) modification for sensitive voltammetric detection of mesalazine (MSA). The characterization of as-synthesized ZIF-67 nanoparticles was investigated by different techniques. Furthermore, the electrochemical behavior of the modified CPE (MCPE) was investigated using EIS (electrochemical impedance spectroscopy) and CV (cyclic voltammetry) methods. The results showed an irreversible oxidation peak for MSA around 0.540 V vs. the Ag/AgCl reference electrode. The curve of the peak current of differential pulse voltammetry (DPV) vs MSA concentration was linear in the range of 0.03�50 μM with a detection limit of 0.01 µM. The prepared sensor presents good repeatability with acceptable relative standard deviation (RSD) values. Finally, the prepared electrode was successfully used in human serum and urine as real samples. © 2020 Elsevier Lt

A new electrochemical sensor for the detection of fentanyl lethal drug by a screen-printed carbon electrode modified with the open-ended channels of Zn(ii)-MOF

Fentanyl is a potent, effective analgesic and narcotic drug widely used for anesthesia and chronic pain control. In this study, a simple electrochemical method for the detection of fentanyl in aqueous solutions was developed. The modification of a screen-printed carbon electrode (SPCE) was performed by casting a metal-organic framework (MOF) on its surface. The characterization of the zinc-based MOF (Zn(ii)-MOF) modifier was investigatedviascanning electron microscopy (SEM), thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR) and X-ray diffraction (XRD) techniques. The differential pulse voltammetry (DPV) technique was used for evaluating the fentanyl electrochemical behavior on the electrodes. The optimum experimental conditions were investigated by examining the effects of the scan rate and pH on the cyclic voltammetry (CV) and DPV responses, respectively. The results showed that fentanyl has an irreversible behavior at the potential of 0.9 V and its current increases in the presence of MOF. The application of the presented electrode with the DPV method showed a detection limit of 0.3 μM in the concentration range of 1-100 μM (linear range) for the fentanyl in an aqueous solution. The modified electrode was successfully used to determine the low levels of fentanyl in urine and plasma as the real samples. © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2020