In this work, three dimensional NiO nanowrinkles (3D NiO-NWs) were prepared and used as electrode materials to modify the surface of a glassy carbon electrode (3D NiO-NWs/GCE). Then, differential pulse voltammetry (DPV), cyclic voltammetry (CV) and chronoamperometry (CHA) were employed to determine the electrochemical response of theophylline on as-fabricated sensor. The electrochemical theophylline oxidation was elevated on the Modified electrode. The peak current on the Modified electrode in phosphate buffer solution (PBS, 0.1 M, pH=7.0) showed a linear elevation with an increase in the theophylline concentration (0.1-900.0 µM), with a narrow detection limit of 0.03±0.001 µM.

In this study, tranexamic acid (Txa) (in 0.1 M Sulfuric acid) Modified glassy carbon electrode (GC) was tested, for the first time, as a sensor for determining the most consumed pain reliever, paracetamol (ACOP) by differential pulse voltammetry (DPV). The tranexamic acid-Modified glassy carbon (rTxa/GC) electrode was characterized by a scanning electron microscope (SEM). Cyclic voltammetry (CV), linear sweep voltammetry (LSV), and electrochemical impedance spectroscopy (EIS) (in aqueous and nonaqueous solution) were used to evaluate the electrochemical performance of electrodes. The Modified electrode increased the oxidation peak current of ACOP significantly in this case. The experimental results provide that rTxa/GC electrode displayed excellent electrocatalytic response to the oxidation ACOP. Additionally, the rTxa/GC electrode exhibited excellent electrocatalytic activity for the electrochemical determination of ACOP in Britton-Robinson (BR) buffer solution with pH values ranging from 2 to 12. As a result, the effective electroactive surface area of rTxa/GC electrode increased by using a BR buffer solution with pH 6. The linear range was 25 – 80 μM for ACOP with a limit of detection (LOD) of 4.7 μM and a limit of detection (LOQ) of 14.2 μM.

In this research project, an electrochemical sensor was developed to sensitively detect oxcarbazepine compound at a new level of glassy carbon using carbon nanotubes. The surface morphology of the resulting Modified electrode was determined by field emission scanning electron microscopy technique (SEM). Under optimal conditions, a significant improvement in the electrochemical behavior of oxcarbazepine was observed at the surface of the Modified electrode compared to the unModified electrode. The results show that the electrocatalytic oxidation process of oxcarbazepine on the surface of the Modified electrode is controlled by the diffusion process and the electrode process is controlled by surface adsorption. Modified electrode by carbon nanotubes due to its high conductivity, good stability, ability to increase the electron transfer rate, and finally, the effective interaction of the analyte with the electrode surface increases the sensitivity in measuring oxcarbazepine compound and its electrocatalytic properties as an electrochemical sensor improved analyte drug measurement. Based on this study, the calibration plots to determine Oxcarbazepine concentrations were linear in the range of 2–40 µM (R2= 00.9912), and the detection limits were found to be 1.9 µM. The results indicate that the proposed method is sensitive, selective, fast, and simple for the determination of Oxcarbazepine.

In this study a facile approach to employ Copper nanoparticle (CuNPs) and multi-walled carbon nanotubes (MWCNT) as the nanomaterial for selective detection of asulam have been investigated. This work reports the electrocatalytic oxidation of asulam on glassy carbon electrodes (GCE) Modified with multi-walled carbon nanotubes (MWCNT), ionic liquids (IL), chitosan (Chit) and copper nanoparticles (CuNPs). Using the proposed nanocomposite provides a specific platform with increased surface. The surface morphology of this Modified electrode was characterized by fieldemission scanning electron microscopy (FE-SEM) and energy dispersive X-ray spectrometer (EDX) techniques. The electrochemical behaviors of the fabricated sensor were investigated by cyclic voltammetry (CV) and chronoamperometry modes. Under optimal conditions, the amperometric study exhibits two linear ranges of 1– 11 and 11– 200 μ mol L-1 with a detection limit (LOD) of 0. 33 nmol L-1 (at an S/N of 3) and sensitivity of 1. 9 nA μ mol L-1 for Asulam determination. This novel sensor was used to analyze the real sample. The sensor provides a convenient, low-cost and simple method for Asulam detection and proposes new horizons for quantitative detection of Asulam.

A thin film of epinephrine (EP) was electrochemically deposited on the surface of glassy carbon electrode previously activated in NaHCO3 solution. The cyclic voltammograms of the Modified electrode indicate that the surface confined EP is strongly dependent on the solution pH, as expected for quinone/hydroquinone functionalities. The EP-Modified glassy carbon electrode exhibited catalytic activity towards the electrooxidation of hydrazine, which appeared as a reduced overpotential especially in pH = 7.5. The diffusion coefficient of hydrazine was estimated using chronoamperometry. The catalytic rate constant, Kh, of the Modified electrode for the oxidation of hydrazine was determined using the cyclic voltammograms recorded at low scan rates as well as the RDE voltammetric approach. It has been shown that the EP-Modified electrode can be used as an amperometric sensor in the analysis of trace amount of hydrazine with high sensitivity and good limit of detection (0.83 µM). Amperometry by EP-Modified electrode was used for determination of hydrazine in boiler feed water and the accuracy of the results was verified by comparison with those obtained from standard ASTM method.