Kamran Polat

A novel carboxymethylcellulose–gelatin–titanium dioxide–superoxide dismutase biosensor; electrochemical properties of carboxymethylcellulose–gelatin–titanium dioxide–superoxide dismutase

A novel highly sensitive electrochemical carboxymethylcellulose-gelatin-TiO(2)-superoxide dismutase biosensor for the determination of O(2)(•-) was developed. The biosensor exhibits high analytical performance with a wide linear range (1.5 nM to 2 mM), low detection limit (1.5 nM), high sensitivity and low response time (1.8s). The electron transfer of superoxide dismutase was first accomplished at the carboxymethylcellulose-gelatin-Pt and carboxymethylcellulose-gelatin-TiO(2)-Pt surface. The electron transfer between superoxide dismutase and the carboxymethylcellulose-gelatin-Pt wihout Fe(CN)(6)(4-/3-) and carboxymethylcellulose-gelatin-Pt, carboxymethylcellulose-gelatin-TiO(2)-Pt with Fe(CN)(6)(4-/3-) is quasireversible with a formal potential of 200 mV, 207 mV, and 200 mV vs Ag|AgCl respectively. The anodic (ks(a)) and cathodic (ks(c)) electron transfer rate constants and the anodic (α(a)) and cathodic (α(c)) transfer coefficients were evaluated: ks(a)=6.15 s(-1), α(a)=0.79, and ks(c)=1.48 s(-1) α(c)=0.19 for carboxymethylcellulose-superoxide dismutase without Fe(CN)(6)(4-/3-), ks(a)=6.77 s(-1), α(a)=0.87, and ks(c)=1 s(-1) α(c)=0.13 for carboxymethylcellulose-superoxide dismutase with Fe(CN)(6)(4-/3-), ks(a)=6.85 s(-1), α(a)=0.88, and ks(c)=0.76 s(-1) α(c)=0.1 carboxymethylcellulose-gelatin-TiO(2)-superoxide dismutase. The electron transfer rate between superoxide dismutase and the Pt electrode is remarkably enhanced due to immobilizing superoxide dismutase in carboxymethylcellulose-gelatin and TiO(2) nanoparticles tend to act like nanoscale electrodes.

Synthesis and Keto‐Enol Tautomerism in N‐(2‐Hydroxy‐1‐Naphthylidene)Anils

New ligands of Schiff bases [(C17H12NOX), X = F, Cl, Br, I] have been synthesised. Intra‐molecular hydrogen bonding and keto‐enamine tautomerism have been studied using IR, 1H‐NMR, 13C‐NMR (DEPT), UV‐Visible and GC‐MS techniques. The UV‐Visible spectra of the compounds have been investigated in different solvents, acidic and basic media. The compounds were in tautomeric equilibrium (enol‐imine O–H···N, keto‐amine O···H–N forms) in polar and nonpolar solvents. The keto‐amine form was observed in basic solutions of DMSO, ethanol, chloroform, benzene, and cyclohexane, and in acidic solutions of chloroform and benzene, but not in acidic solutions of DMSO and ethanol. 1H‐NMR and 13C‐NMR and IR results showed that all Schiff bases studied favor the enol‐imine form over the keto form in a weakly polar solvent such as deuterochloroform solution.

Experimental design of wastewater treatment with electro-coagulation

Purpose – The purpose of this paper is to investigate the batch treatment of pulp and paper mill wastewater using electro-coagulation (EC). Design/methodology/approach – Statistical experimental design was used to investigate the effect of initial pH, current density and temperature. Experiments were planned to obtain the maximum amount of information in the fewest number of runs. Minimum-maximum values of current density, initial pH, temperature of medium were selected as 9-25 mA/cm2, 5-9, 25-50°C, respectively. A total number of 20 experiments including eight factorial points, six axial points and six replicates in centre points were carried out and experimental data were collected. Optimum operating parameters were determined by evaluating experimental results in MATLAB 7.9®. Findings – According to the results, the optimum values of current density, initial pH and temperature of medium are determined as 14.12 mA/cm2, 8.22 and 34.21°C, respectively. Practical implications – Many researches about differ...

Electrochemical oxidation pathway of the anti-cancer agent dasatinib using disposable pencil graphite electrode and its adsorptive stripping voltammetric determination in biological samples

The present study describes the use of pencil graphite electrode (PGE) for the investigation of electro-oxidation mechanism and voltammetric stripping determination of dasatinib (DST) in Britton-Robinson buffer solution (BR). Relating to cyclic voltammetric studies, an irreversible oxidation signal was obtained at about 1.0 V. The oxidation electrode process is adsorption-controlled and pH-dependent. For quantitative determination of DST, square wave adsorptive stripping voltammetry (AdsSWV) was employed in BR of pH 3.0. The oxidation peak current varies linearly with the DST concentration in the range of 0.0092 – 1.0 µ M. Dedection (LOD) and quantification (LOQ) values are founded as 0.0028 µ M and 0.0092 µ M, respectively. The developed AdsSWV method based on disposible and cheap PGE was applied successfuly to the real urine samples and the recovery results are given in the range of 97.94% to 100.82%.