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Öğe A new sensing platform based on NH2fMWCNTs for the determination of antiarrhythmic drug Propafenone in pharmaceutical dosage forms(Elsevier, 2019) Farag, Amir S.; Bakirhan, Nurgul K.; Svancara, Ivan; Ozkan, Sibel A.A novel sensor based on a modification of glassy carbon electrode (GCE) with NH2-functionalized multi walled carbon nano-tubes (NH(2)fMWCNTs) is reported and its applicability to the electrochemical sensing of Propafenone (PPF) demonstrated. The electrochemical catalytic activity was also utilized as a sensitive detection method for the investigation of the detailed redox mechanism of PFF using cyclic and and differential pulse voltammetry. The surface morphology of the sensor was investigated by SEM armed with EDX probe. Electrochemical impedance spectroscopy was employed as well to define the electron transfer capability of modified and bare electrodes. Key experimental and instrumental conditions related to electrochemical determination by cyclic, differential pulse, and square wave voltammetry, such as amount of modifier, pH, scan rate, accumulation time and potential were studied and optimized. The results have shown a significant enhancement of the peak current after modifying the electrode; the calibration curves of PPF offering good linearity from 0.1 to 10 mu M, limit of quantification (LOQ) being 0.03 mu M and limit of detection (LOD) 0.01 mu M, both when using DPV technique. The proposed sensor was successfully applied to the determination of PFF in dosage form without any special purification, separation or pre-treatment steps. The results of analyses obtained with the proposed sensor were satisfactory and fully statistically relevant. (C) 2019 Elsevier B.V. All rights reserved.Öğe A Review: New Trends in Electrode Systems for Sensitive Drug and Biomolecule Analysis(Taylor & Francis Inc, 2020) Ozcelikay, Goksu; Karadurmus, Leyla; Kaya, S. Irem; Bakirhan, Nurgul K.; Ozkan, Sibel A.Drug and biomolecule analysis with high precision, fast response, not expensive, and user-friendly methods have been very important for developing technology and clinical applications. Electrochemical methods are highly capable for assaying the concentration of electroactive drug or biomolecule and supply excellent knowledge concerning its physical and chemical properties such as electron transfer rates, diffusion coefficients, electron transfer number, and oxidation potential. Electrochemical methods have been widely applied because of their accuracy, sensitivity, cheapness, and can applied on-site determinations of various substances. The progress on electronics has allowed developing reliable, more sensitive and less expensive instrumentations, which have significant contribution in the area of drug development, drug and biomolecule analysis. The developing new sensors for electrochemical analysis of these compounds have growing interest in recent years. Screen-printed based electrodes have a great interest in electrochemical analysis of various drugs and biomolecules due to their easy manufacturing procedure of the electrode allow the transfer of electrochemical laboratory experiments for disposable on-site analysis of some compounds. Paper based electrodes are also fabricated by new technology. They can be preferred due to their easy, cheap, portable, disposable, and offering high sensitivity properties for many application field such as environmental monitoring, food quality control, clinical diagnosis, drug, and biomolecules analysis. In this review, the recent electrochemical drug and biomolecule (DNA, RNA, mu RNA, Biomarkers, etc.) studies will be presented that involve new trend disposable electrodes.Öğe Chemical Nanosensors in Pharmaceutical Analysis(Academic Press Ltd-Elsevier Science Ltd, 2019) Kurbanoglu, Sevinc; Bakirhan, Nurgul K.; Shah, Afzal; Ozkan, Sibel A.[Abstract Not Available]Öğe Development of a Surfactant/Platinum Composite for Sensitive Cardio-selective Beta Blocker Detection and their Theoretical Studies(Wiley-V C H Verlag Gmbh, 2019) Zahid, Anum; Bakirhan, Nurgul K.; Karadurmus, Leyla; Shah, Afzal; Ozkan, Sibel A.An electrooxidative behavior of beta-blocker drug esmolol was thoroughly investigated by using glassy carbon electrode modified with sodium dodecyl sulfate-based platinum nanoparticles. The designed nanosensor exhibited remarkable electro-catalytic effect by dramatically boosting the signal of the esmolol as compared to the bare electrode with detection limit up to picomolar. The effects of pH, scan rate, temperature, deposition potential, deposition time, effect of electrolyte and interfering agents were investigated to optimize conditions for getting intense signal of the analyte. Under optimized experimental conditions, a linear calibration plot for esmolol with a detection limit of 60 pM was obtained. The analyte sensing ability of the modified electrode was supported by the application of theoretical studies that showed favorable interaction between sodium dodecyl sulfate/platinum nanoparticles composite and esmolol. In this study, our aim was to developed a nanosensor for the sensitive detection of esmolol by electrochemical assay. We tried a lot of different modification style and modifiers for creating a sensitive nanosensor for esmolol. This nanosensor can be applied to the esmolol in serum sample without using any further separation, evaporation or precipitation steps. Application could apply in serum sample to test accuracy of our sensor and method. The high recovery results were observed in serum study.Öğe Effect of Catalytically Active Zinc Oxide-Carbon Nanotube Composite on Sensitive Assay of Desloratadine Metabolite(Wiley-V C H Verlag Gmbh, 2020) Ozturk, Kubra; Bakirhan, Nurgul K.; Ozkan, Sibel A.; Uslu, BengiDesloratadine is one of the most effective second-generation antihistamines and the electrochemical behavior of the active agent of desloratadine was investigated with a new nanosensor designed with the addition of zinc oxide and multiwalled carbon nanotube (ZnO : MWCNT) mixture on glassy carbon (GCE). By investigating and using cyclic, differential pulse and square wave voltammetry techniques with ZnO : MWCNT/GCE, it is planned to obtain information about quantification and mechanism of desloratadine. The efficiency of experimental parameters such as pH, scan rate, accumulation potential and time on the anodic response of desloratadine were studied. Differential pulse voltammetry was selected as assay method and under developed method and optimized conditions, the current showed linear dependence with concentration in the range between 2x10(-8) and 8x10(-6) M in pH 5.5 acetate buffer. The achieved limits of detection (LOD) and quantification (LOQ) are 0.769 nM and 2.56 nM respectively. Applicability of the methods was demonstrated by their implementation in pharmaceutical dosage forms of desloratadine and the accuracy, precision, selectivity, sensitivity, intra-day and day-to-day reproducibility of the methods were clearly explored. Finally, this sensor was successfully applied on real sample as a selective, simple, reproducible, repeatable an electrochemical sensor.Öğe Effect of Polymer-Based Nanoparticles on the Assay of Antimicrobial Drug Delivery Systems(Elsevier Science Bv, 2017) Gumustas, Mehmet; Sengel-Turk, Ceyda T.; Gumustas, Aysen; Ozkan, Sibel A.; Uslu, Bengi[Abstract Not Available]Öğe Electrochemical Determination and In Silico Studies of Fludarabine on NH2 Functionalized Multiwalled Carbon Nanotube Modified Glassy Carbon Electrode(Wiley-V C H Verlag Gmbh, 2020) Dogan-Topal, Burcu; Bakirhan, Nurgul K.; Tok, Tugba Taskin; Ozkan, Sibel A.A sensitive voltammetric technique has been developed for the determination of Fludarabine using amine-functionalized multi walled carbon nanotubes modified glassy carbon electrode (NH2-MWCNTs/GCE). Molecular dynamics simulations, an in silico technique, were employed to examine the properties including chemical differences of Fludarabine- functionalized MWCNT complexes. The redox behavior of Fludarabine was examined by cyclic, differential pulse and square wave voltammetry in a wide pH range. Cyclic voltammetric investigations emphasized that Fludarabine is irreversibly oxidized at the NH2-MWCNTs/GCE. The electrochemical behavior of Fludarabine was also studied by cyclic voltammetry to evaluate both the kinetic (k(s) and E-a) and thermodynamic (Delta H, Delta G and Delta S) parameters on NH2-MWCNTs/GCE at several temperatures. The mixed diffusion-adsorption controlled electrochemical oxidation of Fludarabine revealed by studies at different scan rates. The experimental parameters, such as pulse amplitude, frequency, deposition potential optimized for square-wave voltammetry. Under optimum conditions in phosphate buffer (pH 2.0), a linear calibration curve was obtained in the range of 2x10(-7) M-4x10(-6) M solution using adsorptive stripping square wave voltammetry. The limit of detection and limit of quantification were calculated 2.9x10(-8) M and 9.68x10(-8) M, respectively. The developed method was applied to the simple and rapid determination of Fludarabine from pharmaceutical formulations.Öğe Magnetic Nanosensor Design and Assay of an Anti-Tuberculosis Drug(Electrochemical Soc Inc, 2019) Imanzadeh, Hamideh; Bakirhan, Nurgul K.; Habibi, Biuck; Ozkan, Sibel A.In the present work, an anti-tuberculosis drug, morphazinamide HCl (MRA) was investigated at ultra-trace level in real sample for the first time. Iron (III) oxide nanoparticles (Fe(2)O(3)NPs) were casted on a glassy carbon electrode (GCE) for the determination of MRA. Cyclic voltammetry, electrochemical impedance spectroscopy, transmission electron microscopy, scanning electron microscopy and energy-dispersive X-ray spectroscopy were employed for morphological characterization of the electrode surface. The results displayed a higher surface area and greater conductivity for the Fe(2)O(3)NPs modified glassy carbon electrode (Fe(2)O(3)NPs/ GCE) than bare GCE. The square wave voltammetry response of the Fe(2)O(3)NPs/GCE was linear with MRA concentration in the range of 1 mu M to 100 mu M under optimized conditions (0.1M phosphate buffer solution at pH 3.0; drop-casting volume 10 mu L; accumulation time 15 s; accumulation potential -0.3 V), with a detection limit of 0.21 nM. Also, the proposed procedure was very efficient for MRA determination from human serum sample with high recoveries. (C) 2019 The Electrochemical Society.Öğe Noble Metal Nanoparticles in Electrochemical Analysis of Drugs(Academic Press Ltd-Elsevier Science Ltd, 2019) Bakirhan, Nurgul K.; Shah, Afzal; Ozkan, Sibel A.[Abstract Not Available]Öğe Optical Nanosensors for Pharmaceutical Detection(Academic Press Ltd-Elsevier Science Ltd, 2019) Nosheen, Erum; Shah, Afzal; Iftikhar, Faiza Jan; Aftab, Saima; Bakirhan, Nurgul K.; Ozkan, Sibel A.[Abstract Not Available]Öğe Recent Electrochemical Assays on Cephalosporins(Bentham Science Publ Ltd, 2020) Karadurmus, Leyla; Esme, Kaan; Bakirhan, Nurgul K.; Ozkan, Sibel A.Antibiotics are an important class among drugs because they are a significant agent to deal with infections. Cephalosporins are a very important group of antibiotics in the beta-lactam class. The cephalosporins are semisynthetic antibiotics derived from products of the fungus Cephalo-sporium. Cephalosporins are classified as first, second, third, fourth, and advanced generation, based largely on their antibacterial spectrum and stability to beta-lactamases. Electrochemical methods have been used for the determination of cephalosporin just as used in the determination of many antibiotic drugs. Electroanalytical methods present generally high sensitivity, low cost, low requirements, ease of preparation of the samples in a very short time, and a short analysis time. The most commonly used types are cyclic voltammetry, differential pulse voltammetry, square wave voltammetry and linear sweep voltammetry. The aim of this review is to evaluate the advantages and uses of electroanalytical methods used in the determination of cephalosporins. In addition, current applications of the methods to the pharmaceutical analysis of cephalosporins will also be summarized in a table.Öğe THE RECENT ELECTROCHEMICAL STUDIES ON BISPHENOL A DETECTION IN BEVERAGES(Woodhead Publ Ltd, 2020) Bakirhan, Nurgul K.; Ozkan, Sibel A.[Abstract Not Available]Öğe The Role and the Place of High-Performance Liquid Chromatography for the Determination of Fermented Dairy Products(Academic Press Ltd-Elsevier Science Ltd, 2017) Gumustas, Mehmet; Uslu, Bengi; Ozkan, Sibel A.[Abstract Not Available]Öğe Turning toxic cigarette butt waste into the sensor material for the sensitive determination of antihypertensive drug trandolapril from its dosage form and biological samples(Elsevier Science Sa, 2019) Bilge, Selva; Bakirhan, Nurgul K.; Donar, Yusuf Osman; Sinag, Ali; Ozkan, Sibel A.The findings of this study revealed that hydrothermal carbonization (HTC) of filter parts of smoked cigarette butts generates carbonaceous materials that have porosity and high surface area (1012 m(2) g(-1)). This method is relatively eco-friendly because it performed in closed system and under mild conditions. In this study, porous carbon obtained from HTC of smoked cigarette filters was applied in an electroanalytical drug analysis. The surface morphology and chemical structure of the as-prepared materials were illuminated using with different techniques. The voltammetric behavior of antihypertensive drug trandolapril (TRD) was investigated on glassy carbon electrode (GCE) that modified by cigarette filter derived char/Nitrogen doped carbon spheres (c-char/NCS). The electrooxidation of TRD was demonstrated a diffusion-controlled fashion at pH 3.0 phosphate buffer (PB) solution. The calibration curve was linear between 8 x 10(-8) and 8 x 10(-5) M. The detection limit (LOD) was obtained as 1.09 x 10(-10) M in pH 3.0 PB solution and 2.57 x 10(-8) M in human serum samples by DPV. We try to show that the novel electrochemical sensor was easily applied for the determination of TRD using various carbon structures produced from urea and filter parts of cigarette butts.
