-
Article
1 - Modified Glass Carbon Electrode (GCE) Electropolymerized Polypyrrole Nanofibers with Hemoglobin (Hb) Film as a Unique Biosensor for Nitrite DeterminationJournal of Optoelectronical Nanostructures , Issue 2 , Year , Summer 2020Abstract: In this study, we were investigated behavior the electrochemical reduction
of nitrite at a hemoglobin (Hb) immobilized on glass carbon electrode (GCE) containing
polypyrol nanofiber (ppy) films. Polypyrrole (PPy) nanofibers have been constructed onMoreAbstract: In this study, we were investigated behavior the electrochemical reduction
of nitrite at a hemoglobin (Hb) immobilized on glass carbon electrode (GCE) containing
polypyrol nanofiber (ppy) films. Polypyrrole (PPy) nanofibers have been constructed on
GCE applying electrochemical technique, and can to deposit diverse polymers on
miniaturized electrodes with this common method. The structure of the acquired
electrode and the electrochemical behavior were characterized using Scanning Electron
Microscopy (SEM), Cyclic Voltammetry (CV), and Linear Sweep Voltammetry (LSV).
The immobilized Hb showed an irreversible reduction peak with a formal potential of –
0.72 versus Ag/AgCl, in 0.1M pH 4.5 acetate buffer. The immobilized Hb exhibited
remarkable electrocatalytic activity for the reduction of nitrite. Under the optimal
condition the nitrite concentrations range 2.0×10−4 to 46.0×10−4 M with a detection limit
of 6.2×10−5 M (at S/N=3). The resulting biosensor has been successfully applied to the
determination of nitrite in water samples. The produced modified electrode for nitrite
determination has been explored within the presence of the interfering substances
including a number of common ions and cations, demonstrating great selectivity. Manuscript profile -
Article
2 - Electrocatalytic Determination of Captopril on Gold Nanoparticle-Modified Carbon Paste Electrode.Journal of Optoelectronical Nanostructures , Issue 5 , Year , Winter 2022The 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 mar MoreThe 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 1.0V (versus Ag/AgCl) is obtained using the prepared modified electrode. Captopril oxidation on CPE/GNPs proceeds at pH between 4.0 and 10.0. Under the optimized conditions, the electrocatalytic oxidation peak current of captopril showed two linear dynamic ranges with a detection limit of 8.28×10-2 µM captopril. The linear calibration range was 1.14-16.98 and 21.49-62.1 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. Manuscript profile