تهيه الكترودهاي كربن نانولوله ايي و اصلاح ساختار آنها با استفاده از تركيبات الكتروكاتاليست به عنوان سنسورهاي الكتروشيميايي براي اندازه گيري برخي از داروها

چكيده انگليسي :

Preparation of Carbon Nanotube Electrodes and Modified Their Structures as Electrochemical Sensors for Determination of some Drug Using Electrocatalyst Compounds Elaheh Khoddami elaheh khoddami@yahoo com Department of Chemistry Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Ali A Ensafi Email Ensafi@cc iut ac ir Abstract Penicillamine is a pharmaceutical of the chelator class It is used as a form of immunosuppressant in the treatment of rheumatoid arthritis Penicillamine is also used as a chelating agent For example in cystinuria a hereditary disorder featuring formation of cystine stones penicillamine binds with cysteine to yield a mixed disulfide which is more soluble than cystine Isoprenaline or isoproterenol is a catecholamine drug that causes arterial and bronchial dilation and is sometimes administered via aerosolization as a bronchodilator to treat bronchial asthma and bronchospasm Isoprenaline is used as heart motive in aritmi Uric acid the end metabolic product of purine through liver is present in urine and blood UA variations are monitored in body fluids as a powerful indicator for early diagnosis of kidney diseases The first we describe simultaneous voltammetric determination of penicillamine PA in the presence of uric acid UA using a paste electrode PE that is consist of p aminophenol as a mediator and multiwall carbon nanotubes with TiO2 nanoparticle for rapid sensitive and highly selective determination The electrochemical behavior of the compounds at this modified electrode was studied by cyclic voltammetry CV differential pulse voltammetry DPV and electrochemical impedance spectroscopy EIS The results indicated that the chemically modified electrode exhibits efficient electrocatalytic activity in the oxidation of PA which occurs at a potential of about 530 mV less positive than that for the unmodified carbon nanotubes paste electrode at pH 6 0 PA and UA in a mixture can be measured independently from each other with a potential difference of 215 mV using DPV The results showed that UA cannot catalysis at a surface of the modified carbon naotubes TiO2 paste electrode At pH 6 0 the catalytic peak currents were linearly dependent on PA and UA concentrations in the ranges 0 4 200 mol L 1 PA and 3 0 1000 mol L 1 UA Detection limits for PA and UA were 0 1 mol L 1 and 1 1 mol L 1 respectively The relative standard deviation RSD for 1 2 and 1 5 mol L 1 PA were 1 6 and 2 1 respectively whereas they were 1 5 and 1 1 for 15 0 and 30 0 mol L 1 UA respectively The kinetic parameters such as electron transfer coefficient 0 38 and catalytic reaction rate constant Kh 2 58 103 M 1 s 1 were also determined using electrochemical approaches The diffusion coefficient for PA at the surface of p aminophenol modified carbon nanotubes TiO2 paste electrode was determined 7 14 10 5 cm2 s 1 Finally the sensor was examined as a selective simple and precise new electrochemical sensor for the determination of PA in real samples with application standard addition method in drugs and urine Finally a sensitive and selective electrochemical method for the determination of isoproterenol ISPT was developed by using a ferrocene multiwall carbon nanotubes paste electrode FCMWCNTPE The fabrication of FCMWCNTPE and its electrocatalytic effect for the electrochemical oxidation of ISPT were investigated by electrochemical impedance spectroscopy and voltammetric methods The cyclic voltammetric results indicate that multiwall carbon nanotubes remarkably enhance the oxidation of ISPT at pH 5 0 which is leading to considerable improvement of anodic peak current for ISPT and allow the development of a highly sensitive voltammetric sensor for determination of ISPT in pharmaceutical and urine samples It has been found that under the optimum condition pH 5 0 in cyclic voltammetry the oxidation of ISPT occurred at a potential about 140 mV less positive than that unmodified carbon paste electrode The kinetic parameters

خدامي، الهه

تهيه الكترودهاي كربن نانولوله ايي و اصلاح ساختار آنها با استفاده از تركيبات الكتروكاتاليست به عنوان سنسورهاي الكتروشيميايي براي اندازه گيري برخي از داروها

پل سيل آمين , اوريك اسيد , ايزوپروترنول , پاراآمينوفنول , فروسن , الكترودهاي خمير نانو لوله هاي كربني چند ديواره اصلاح شده ,