فهرست مطالب tahere kondori

Three novel Cr(III) complexes, [Cr(dafone)2(H2O)2](NO3)3 (1), [Cr(opd) (dafone)2](NO3)3 (2) and [Cr (phen-dione) (dafone) (H2O)2].(NO3)3 (3) were synthesized and characterized by different techniques. Fluorescence spectroscopy, gel electrophoresis, viscosity measurement, and circular dichroism (CD) were applied to explore the interaction of Cr complexes with FS-DNA. The binding constant (Kb) was obtained from UV–Vis measurements. The obtained results exhibited the effective binding of target complexes to DNA double-strand. The fluorescence data appraised both binding and thermodynamic constants of complexes-DNA interactions. The measured thermodynamic factors (∆S˚, ∆H˚, ∆G˚) revealed that hydrogen bonding and van der Waals forces for DNA- Cr(III) complexes bear the most important roles. As well, the Stern–Volmer quenching constants (Ksv) and the binding constants (Kb) of synthesized compounds and DNA were calculated. The results of thermodynamic parameters showed that the binding of synthesized Cr(III) compounds to DNA was driven mainly through hydrogen bonds and van der Waals interactions. Viscosity measurement results showed that increasing the concentration of synthesized compounds, did not make any major changes in specific viscosity of FS-DNA. The data of viscosity and circular dichroism (CD) support the groove binding mode.

In this study, nickel oxide nanoparticles was prepared by co-precipitation method and characterized using FT-IR, XRD, VSM and SEM techniques. By Fourier transform infrared FT-IR has proven bond forming of NiO in nickel oxide. . X-ray diffraction (XRD) showed that the single-phase sample had a cubic symmetry with a particle size of 57 nm. Nickel oxide nanoparticles can be prepared as an efficient adsorbent for the removal of food color in aqueous solution. The highest removal percentage of food color, was in pH=7 and it,s concentration was 15 ppm. The obtained experimental data in optimum condition was used to model the behavior of absorption in isotherms equations such as: Langmuir, Freundlich, Langmuir-Freundlich and Toth. An examination of the Langmuer isotherm (R2=0.980) showed that the absorption of food color on the adsorbent surface was monolithic and uniform. The kinetics of adsorption interactions were examined. The obtained results showed that the adsorption data has the most conformity with, pseudo-second-order model.

In this investigation, we have reported the synthesis of the complex [Th(5,5´-dmbpy)3](NO3)4](1) that 5,5´-dmbpy =5,5´-dimethyl-2,2´-bipyridine. This complex has been characterized using spectral methods (FT-IR, UV-Vis, 1H-NMR and luminescence), elemental analysis and the Cyclic Voltammetry (CV) method. The FT-IR data shows that 5,5´-dimethyl-2,2´-bipyridine (5, 5´- dmbpy) ligand adduct to metal centers by nitrogen atoms. Electronic spectra of (1) shows ligand field transitions and charge transfer (CT) bands. Electrochemical data for the complex in the DMF solution show reduction and oxidation processes for the Thorium ion and ligand. The interactions of complex (1) with FS-DNA have been investigated using UV–Vis and gel electrophoresis. The binding constant (Kb) was calculated using UV–Vis technique (Kb=3.5×105). Also, DNA cleavage was studied using agarose gel electrophoresis. The antibacterial properties and fluorescence property of complex (1) have also been examined. The in vitro biological screening effects of the complex and ligand were tested against different types of bacterium and [Th(5,5´-dmbpy)3](NO3)4](1) shows antibacterial properties.

Folate is another form of folic acid, which is known as one of the B vitamins. It is utilized as an additive by women during pregnancy in order to prevent the neural tube defects. The present study reports on the fabrication of electrochemical sensor for the determination of folic acid using Co3O4 nanoparticles. The suitability of Co3O4 nanoparticles as a modifier for the electrocatalytic detection of folic acid in aqueous solution was investigated by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and chronoamperometry (CA) techniques. The fabricated Co3O4 NPs/GCE sensor exhibited sharp and intense peak towards the electro-oxidation of folic acid as compared to bare electrode. The linear calibration plot of folic acid was obtained from 1.0 to 900.0 µM with the detection limit of 0.8 µM. The modified electrode was use for the detection of folic acid in real samples and found to produce satisfactory results.