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In this study, simultaneous determination of toxic hydrazine and nitrite was performed on composite electrodes of poly(Nile blue)(NB), carbon nanotube(CNT) and gold nanoparticles(AuNPs). The prepared AuNPs/CNT/poly(NB)/GCE was used for as a sensor platform for individual and simultaneous determination of hydrazine and nitrite. Electrodes were characterized by HRTEM, SEM, XPS, EIS. The LOD for nitrite and hydrazine was 5.0 mu M and 3.1 mu M at AuNP/CNT/poly(NB)/GCE, respectively. Also, sensitive amperometric determinations of hydrazine and nitrite were performed and LOD were calculated as 0.33 mu M and 0.68 mu M, respectively. The method was applied to sausage and river water samples and recovery results were obtained in the range 85-115 %.

A glassy carbon electrode, modified with gold nanoparticles/over-oxidized poly-eriochrome black T film, was fabricated for sensitive determination of As(III) by stripping voltammetry in an acidic medium. The electrode surface properties were characterized by cyclic voltammetry, electrochemical impedance spectroscopy, scanning electron microscope (SEM), and X-ray photoelectron spectroscopy (XPS). The electrode demonstrated a good response towards As(III), with a detection of 0.077 ?M and good linearity in the range of $0.1 to 10 ?M (R^2 = 0.9977)$. For the determination of As(III), the fabricated electrode was placed in different mineral water samples, acidified with 0.75 M HCl solution, spiked with various concentrations of As(III). Spiked recoveries for mineral water samples were obtained in the range of 100.3%–105.0%. The relative standard deviations were lower than 4.0%.

This study reports a detailed analysis of an electrode material containing poly(phenolphthalein), carbon nanotubes and gold nanoparticles which shows superior catalytic effect towards to hydrazine oxidation in Britton-Robinson buffer (pH 10.0). Glassy carbon electrode was modified by electropolymerization of phenolphthalein (PP) monomer (poly(PP)/GCE) and the multiwalled carbon nanotubes (MWCNTs) was dropped on the surface. This modified surface was electrodeposited with gold nanoparticles (AuNPs/CNT/poly(PP)/GCE). The fabricated electrode was analysed the determination of hydrazine using cyclic voltammetry, linear sweep voltammetry and amperometry. The peak potential of hydrazine oxidation on bare GCE, poly(PP)/GCE, CNT/GCE, CNT/ poly(PP)/GCE, and AuNPs/CNT/poly(PP)/GCE were observed at 596 mV, 342 mV, 320 mV, 313 mV, and 27 mV, respectively. A shift in the overpotential to more negative direction and an enhancement in the peak current indicated that the AuNPs/CNT/poly(PP)/GC electrode presented an efficient electrocatalytic activity toward oxidation of hydrazine. Modified electrodes were characterized with High-resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and electrochemical impedance spectroscopy (EIS). Amperometric current responses in the low hydrazine concentration range of 0.25-13 µM at the AuNPs/CNT/poly(PP)/GCE. The limit of detection (LOD) value was obtained to be 0.083 µM. A modified electrode was applied to naturel samples for hydrazine determination. © This work is licensed under a Creative Commons Attribution 4.0 International License., 2018-097, This work was supported by Manisa Celal Bayar University Research Foundation Project No: 2018-097. Part of the SEM experiments in this article were performed at Manisa Celal Bayar University (Turkey)-Applied Science and Research Center (DEFAM).

Zinc oxide nanoparticles doped graphene oxide modified glassy carbon electrodes (Zn-GO/GCE) were fabricated for easy, cheap and practical detection of atenolol (ATE). the morphological and chemical characterizations of modified electrodes were carried out with scanning electron microscopy (SEM), electron diffraction spectroscopy (EDS) and X-Ray photoelectron spectroscopy (XPS). the amounts of the electrode modifiers and the differential pulse voltammetric parameters were optimized due to exhibited the best analytical response towards the determination of ATE. As a result, the calibration curves of ATE were obtained at Zn-GO/GCE using DPV technique with two different linear parts: 7.8 - 84 mu mol L(-1)and 167 mu mol L-1- 639 mu mol L-1. the detection limit (LOD) was also calculated as 2.50 mu mol L-1. the fabricated electrode in this study is selective for ATE in the presence of some electroactive molecules. the practical, easy and cheap modified electrode was applied for the detection of ATE in atenolol medicine tablets with good recovery., BAP ProjectTurkiye Cumhuriyeti Kalkinma Bakanligi [17 FEN 079], The authors gratefully acknowledge the support of this work by Funds (BAP Project No: 17 FEN 079).

Dimethylamine borane (DMAB) is a promising fuel alternative for fuel cell applications. In this work cyclic voltammetric behavior of DMAB was investigated on the polymerized aminophenol film decorated with Ag nanoparticles in alkaline media. The polymer film was formed on the glassy carbon electrode by electrochemical technique and then, the surface was modified with Ag nanoparticles. The surface of the modified electrode was identified by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and electrochemical impedance spectroscopy techniques. The developed electrode has displayed high electrocatalytic activity for DMAB oxidation in alkaline media depending on the supporting electrolyte concentration. Experimental parameters such as cycle number used in electropolymerization of p-aminophenol, deposition of Ag nanoparticles and supporting electrolyte were optimized.

Electrochemical behaviour of oxygen was investigated at nickel-copper bimetallic particles covered into poly (ethylenedioxythiophene) modified glassy carbon electrode (Ni-Cu/PEDOT/GCE). the characterization tools which are energy-dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and electrochemical impedance spectroscopy (EIS) were used to identify the mor-phology and chemical structure of the modified electrode surfaces. the best catalytic effect regarding to peak potential and peak current for O-2 reduction were obtained with the Ni-Cu/PEDOT/GCE. the hydrodynamic studies have shown that the reduction of oxygen occurs via almost four electron transfer on the Ni-Cu/PEDOT/GCE., Ege University Research Funds (BAP project)Ege University [2012 FEN/077], This work was supported by Ege University Research Funds (BAP project, 2012 FEN/077).

Dimethylamine borane (DMAB) is a promising fuel alternative for fuel cell applications. In this work cyclic voltammetric behavior of DMAB was investigated on the polymerized aminophenol film decorated with Ag nanoparticles in alkaline media. The polymer film was formed on the glassy carbon electrode by electrochemical technique and then, the surface was modified with Ag nanoparticles. The surface of the modified electrode was identified by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and electrochemical impedance spectroscopy techniques. The developed electrode has displayed high electrocatalytic activity for DMAB oxidation in alkaline media depending on the supporting electrolyte concentration. Experimental parameters such as cycle number used in electropolymerization of p-aminophenol, deposition of Ag nanoparticles and supporting electrolyte were optimized. © TÜBİTAK.

WOS: 000501620800017, Herein, a new facile and sensitive method was developed that enables the individual and simultaneous determination of catechol (CC) and hydroquinone (HQ) using an over-oxidized and electrochemically polymerised rutin film glassy carbon electrode. the proposed electrode exhibits a large peak potential difference between CC and HQ resulting in well-separated peaks-an important factor for selective determination. CC and HQ were individually and simultaneously determined via differential pulse voltammetry in a pH -7.2 phosphate buffer solution. the individually calculated detection limits for CC and HQ were 8.8 and 52 nM, respectively. in simultaneous determination, the limits of detection were calculated to be 31 and 53 nM for CC and HQ respectively. Moreover, real sample analyses were successfully conducted using tap and waste water. (C) 2019 Elsevier B.V. All rights reserved.

EgeUn###, The attractive features of nanomaterials enable them to be used in a variety of areas including drug delivery (DD) systems. The advantages like better targeting and effective delivery, promote the usage of these materials in the structure of DD. However, the hazardous effects of nanomaterials must be considered before allowing them to be utilized in vivo. Because of their metallic based natures and small dimensions, nanomaterials can be toxic to human beings. Therefore the cons and pros of the usage of nanomaterials in DD systems must be extensively considered. In this review, after the brief history of DD systems and the usage of nanomaterials in these systems were presented, the selected nanomaterials cons and pros towards DD were examined. In conclusions and feature perspective part, the inadequacy of numbers of in-vivo studies was discussed and the need for more in-vivo tests was emphasized.

Oxygen reduction reaction was investigated in an O2-saturated 0.1 M NaOH solution at Au(111) single crystal electrodes modified with various ad-metals (Cu, Ag and Bi) by underpotential deposition (upd). An increase in the catalytic activity was observed upon deposition of metal ad-atoms submonolayer for all prepared electrodes: Cu ad-layer was found, for the first time, to show a very interesting positive catalytic effect in contrast with reported data in acidic media, i.e., an apparent four-electron reduction process due to considerable enhancement of the disproportionation of hydrogen peroxide on the 1/3 monolayer (ML) Cu-modified Au(111) electrode. An interesting catalytic activity was also obtained at the 1/3 ML Ag ad-atoms modified Au(111) electrode, where a significant increase in reduction current was shown to suggest a four-electron reduction of oxygen to water. The Bi ad-atoms modified Au(111) electrode, Bi(2×2)–Au(111), showed positive catalytic activity by a limiting current of twice higher than at a bare Au(111) electrode with peak potential at ca. −0.38 V vs. Ag|AgCl|KCl(sat). Keywords: Fuel cells, Oxygen reduction, Electrocatalytic activity, Au(111) electrode, upd

Surface functions of modified electrodes for the rapid electron transfer of cytochrome c have been examined by using new surface modifiers. 2-Mercaptopyrazine (2-PyZSH) and 2-mercaptoquinoxaline (or 2-mercaptobenzopyrazine, 2-MQ) modified Au(111) electrodes gave well-defined cyclic voltammmograms of cytochrome c, while a 2-mercaptopyridine (2-PySH) modified electrode gave no response. The STM images of 2-PySH and 2-PyZSH modified surfaces were similar to each other, suggesting 2-PySH and 2-PyZSH adsorbed at both thiolate S and pyridine (or pyrazine) N atoms with pyridine (or pyrazine) ring being perpendicular to the electrode surface. The 2-PyZSH modified surface has another pyrazine N atom faced to the solution, through which cytochrome c can interact, and the double layer capacitance data of the electrode gave more hydrophilic nature than the 2-PySH modified surface. On the other hand, although 2-MQ was suggested to adsorb on the electrode in a similar manner to 2-PySH and 2-PyZSH to give N atom at the solution side, the 2-MQ modified surface showed less hydrophilicity than the 2-PySH modified surface due to the quinoxaline ring. These results clearly reveal that the pyridine and pyrazine N atoms faced to the solution (rather than the hydrophilicity of the electrode surface) are important for the rapid electron transfer of cytochrome c on these modified electrodes. Keywords: Surface function, Surface modifier, Au single crystal electrodes, STM image, Cytochrome c, Cyclic voltammetry

Multiwalled carbon nanotubes (MWCNTs) were functionalized with acid treatment and thereafter gold-copper nanoparticles were electrodeposited on the MWCNTs by applying several repetitive scans, thus forming a Cu-Au-MWCNT/GCE interface. The electrochemical reduction of oxygen was studied on this modified electrode in 0.1 M NaOH solution. The electrocatalytic activity on the Cu-Au-MWCNT/GCE showed a tendency towards the O-2 reduction. The peak potential of O-2 reduction on the Cu-Au-MWCNT/GCE shifted ca. 70 mV higher positive potentials as compared to that of a polished glassy carbon electrode. A significant current enhancement was obtained on the Cu-Au-MWCNT/GCE compared to that of bare GCE, MWCNT/GCE, Cu-MWCNT/GCE and Au-MWCNT/GCE. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were employed in order to investigate the surface morphology and elemental composition of the modified electrode, respectively. (C) 2011 Elsevier B.V. All rights reserved.

Background: The purpose of this study is to evaluate the nephrotoxicity of sevoflurane inhalation anesthesia applied during carbon dioxide pneumoperitoneum ( CO2-PNP) which is conducted for a laparoscopic surgery treatment. Materials and Methods: 14 New Zealand white rabbits were used in this study. Initially, anesthesia was induced using 3.7% concentrated sevoflurane + 50% O-2/N2O. Then, a tracheotomy was performed, and the rabbits were mechanically ventilated. The first group ( n = 7) was subjected to CO2-PNP for 90 min with a constant intraabdominal pressure of 12 mm Hg, the second ( control group) ( n = 7) was exempted. The serum inorganic fluoride ( IF-) concentration was measured. The rabbits were sacrificed after 72 h, and one kidney each was immediately extracted for histopathological examination. Results: Serum IF- concentrations were not different in both groups. Histopathologically, mild renal damage was found in one rabbit in each group. Conclusion: CO2-PNP did not have any additional effect on the nephrotoxicity of sevoflurane.

WOS: 000380707100007, PubMed ID: 30460294, Ammonia borane is widely used in most areas including fuel cell applications. The present paper describes electrochemical behavior of ammonia borane in alkaline media on the poly(p-aminophenol) film modified with Au and Ag bimetallic nanoparticles. The glassy carbon electrode was firstly covered with polymeric film electrochemically and then, Au, Ag, and Au-Ag nanoparticles were deposited on the polymeric film, respectively. The surface morphology and chemical composition of these electrodes were examined by scanning electron microscopy, transmission electron microscopy, electrochemical impedance spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. It was found that alloyed Au-Ag bimetallic nanoparticles are formed. Electrochemical measurements indicate that the developed electrode modified by Au-Ag bimetallic nanoparticles exhibit the highest electrocatalytic activity for ammonia borane oxidation in alkaline media. The rotating disk electrode voltammetry demonstrates that the developed electrode can catalyze almost six-electron oxidation pathway of ammonia borane. Our results may be attractive for anode materials of ammonia borane fuel cells under alkaline conditions., Scientific and Technical Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [110T806]; EBILTEMEge University [BIL-012]; Ege University Research Funds (BAP project)Ege University [10 FEN/075], This work was supported by the Scientific and Technical Research Council of Turkey (TUBITAK) with 110T806 project number, EBILTEM with BIL-012 project number, and Ege University Research Funds (BAP project, 10 FEN/075). The author thanks the Associate Prof. Dr. Armagan Kinay for his careful reading of the manuscript.