An electrochemical sensor based on manganese dioxide nanorodMnO2and Graphene oxide (GO) functionalized with 4-amino, 3-substituted 1H, 1, 2, 4 Triazole 5(4H) thion (FGO)/MnO2Nanocompositewas developed for voltammetric determination of Tetracycline (TET).The working electrode WE of SPCE was modified bya drop casting method. X-ray powder diffractometer (XRD), scanning electron microscopy (SEM) and FT-IR were employed to characterize the synthesized FGO/MnO2. The determination of TET at the modified electrode was studied by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) in the phosphate buffer solution (PBS).TET show sharp increase in the oxidation peaks in the pH 2.Voltammetric characteristics of TET (Epa, Ipa) were estimated. From effect of scan rate, the average surface coverage (Γ) of TET on the surface of SPCE modified with FGO/MnO2 nanocomposite, the electron transfer coefficient and electron transfer constant rate ket was obtained as 10.56×1014 molecule cm-2, 0.5, and 10.41 cm.s-1respectively. Under the optimal conditions, the peak current shows linear relationship with concentration of Tetracycline (TET) ranges 1–9 μM with the detection limit of 0.2μ M. The modified SPCE was successfully used to detect TET
In this study, bauxite and modified bauxite /polymer, which were prepared as an adsorbent surfaces to adsorption of the tetracycline from aqueous solutions. A series of adsorption experiments were conducted to determine the equilibrium time and temperature effect on the adsorption process. The results showed that adsorption was agreed with the Freundlich equation model for the surface of the bauxite. As for the modified bauxite surface, the results were consistent with the Langmuir equation model. The values of the basic thermodynamic functions of the adsorption process were calculated, so the process of adsorption was founded spontaneous and endothermi
The direct electron transfer behavior of hemoglobin that is immobilized onto screen-printed carbon electrode (SPCE) modified with silver nanoparticles (AgNPs) and chitosan (CS) was studied in this work. Cyclic voltametry and spectrophotometry were used to characterize the hemoglobin (Hb) bioconjunction with AgNPs and CS. Results of the modified electrode showed quasi-reversible redox peaks with a formal potential of (-0.245 V) versus Ag/AgCl in 0.1 M phosphate buffer solution (PBS), pH7, at a scan rate of 0.1 Vs-1. The charge transfer coefficient (α) was 0.48 and the apparent electron transfer rate constant (Ks) was 0.47 s-1. The electrode was used as a hydrogen peroxide biosensor with a linear response over 3 to 240 µM and a detection li
... Show More
This study involved preparation of Graphene oxide (GO) and reduced graphene oxide (RGO) using Hummer method and chemical method respectively. These carbon nanomaterials were used as starting material to make novel functionalize with thiocarbohydrazide (TCH) which was prepared by reacting CS2 with hydrazine to form GO or RGO- 4-amino,5-substituted 1H,1,2,4 Triazole 5(4H) thion (ASTT) ,(GOT) and( RGOT) respectively via cyclocondensation reaction. Also MnO2 nanorod was prepared to form hybridized with GOT and RGOT. A commercial multiwall carbon nanotube (MWCNT) and functionalization with carboxylic groups' (f-MWCNT) and its nanocomposite with GOT were also prepared. All carbon nanomaterials were characterized with different techniques such as
... Show MoreThere is currently a pressing need to create an electro-analytical approach capable of detecting and monitoring genosensors in a highly sensitive, specific, and selective way. In this work, Functionalized Multiwall Carbon Nanotubes, Graphene, Polypyrrole, and gold nanoparticles nanocomposite (f-MWCNTs-GR-PPy-AuNP) were effectively deposited on the surface of the ITO electrode using a drop-casting process to modify it. The structural, morphological, and optical analysis of the modified ITO electrodes was carried out at room temperature using X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) images, atomic force microscopy (AFM) and Fourier transform infrared (FTIR) spectra. Cyclic voltammetry (CV) and electrochemi
... Show MoreModified algae with nano copper oxide (CuO) were used as adsorption media to remove tetracycline (TEC) from aqueous solutions. Functional groups, morphology, structure, and percentages of surfactants before and after adsorption were characterised through Fourier-transform infrared (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS). Several variables, including pH, connection time, dosage, initial concentrations, and temperature, were controlled to obtain the optimum condition. Thermodynamic studies, adsorption isotherm, and kinetics models were examined to describe and recognise the type of interactions involved. Resultantly, the best operation conditions were at pH 7, contact time
... Show More
(25)
Modified algae with nano copper oxide (CuO) were used as adsorption media to remove tetracycline (TEC) from aqueous solutions. Functional groups, morphology, structure, and percentages of surfactants before and after adsorption were characterised through Fourier-transform infrared (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS). Several variables, including pH, connection time, dosage, initial concentrations, and temperature, were controlled to obtain the optimum condition. Thermodynamic studies, adsorption isotherm, and kinetics models were examined to describe and recognise the type of interactions involved. Resultantly, the best operation conditions were at pH 7, contact time
... Show More
(27)
(25)
Glassy carbon electrode (GCE) was modified with carbon nanotubes CNT and C60 by attachment and solution evaporation techniques, respectively. CNT/Li+/GCE and C60/Li+/GCE were prepared by modifying CNT/GCE and C60/GCE in Li+ solution via cyclic voltammetry (CV) potential cycling. The sensing characteristics of the modified film electrodes, demonstrated in this study for interference of Mn2+ in different heavy metals ion esp. Hg2+, Cd2+ and Cu2+. The interfering effect was investigated that exert positive interference on the redox peaks of Mn2+. The modification of GCE with nano materials and Li+ act an enhancement for the redox current peaks to observe the effect of interference for Mn2+ in 1:1 ratio with different heavy metals ion.
(3)
(44)
A simple, sensitive, accurate and low cost effective spectrophotometric method has been developed for the determination of Tetracycline and Doxycycline in pure and pharmaceutical formulations. The method is based on the reaction of methyldopa with 4-aminoantipyren (4-AAP) in presence of potassium ferriecyanide (PFC) in an alkaline medium. Two optimization methods were applied to determine the optimum conditions of oxidizing coupling reaction variables; univariate and design of experiment (DOE) method. The conditions effecting the reaction; pH, buffer Volume, reagent concentration, oxidant concentration, type of buffer, order of addition, time of reaction and stability were optimized . Under univariate and design
... Show MoreA simple, fast and sensitive spectrophotometric method has been applied for the determination of tetracycline hydrochloride in its pure form and in pharmaceutical preparations. The method based on coupling reaction of the antibiotic with diazotized anthranilic acid to form a stable yellow azo dye which shows a maximum absorption at 419 nm. Uni- and multivariate approaches were followed in optimizing the experimental conditions. Under optimum experimental conditions obtained via multivariate (Central Composite Design), the linearity of the constructed calibration curve was in the range of 0.560 μg.mL-1 with molar absorptivity of 14619 L.mol-1.cm-1 and the value of detection limit was 0.2813μg.mL-1. The capability of the metho
... Show More
(1)