Development of Cu2O/Carbon Vulcan XC-72 as Non-Enzymatic Sensor for Glucose Determination
ABSTRACT A novel and stable non-enzymatic glucose sensor was developed based on the chemical reduction of Cu(2)O nanoparticles on Carbon Vulcan XC-72 using NaBH(4) as the reducing agent via the impregnation method. Different molar ratios of NaBH(4) to the copper salt were employed during the reduction step. This was found to affect the morphology; composition and structure of the prepared samples as investigated by TEM, EDX and XRD analyses. Cyclic voltammetry and chronoamperometry were applied to examine the electrocatalytic activity of the different samples of Cu(2)O/Carbon Vulcan XC-72 towards glucose oxidation in alkaline medium. The 'x70' sample got the highest oxidation current density and the lowest oxidation potential. The performance of this sensor was evaluated showing a wide linear range up to 6mM with sensitivity of 629 μA cm(-2)mM(-1) and detection limit of 2.4 μM. Its good tolerance to ascorbic acid with long-term stability elects Cu(2)O/Carbon Vulcan XC-72 as a promising glucose sensor.
Full-textDOI: · Available from: K. M. El-Khatib, Jan 15, 2015
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ABSTRACT: Nano PtCuO particles were deposited on Vulcan XC-72R carbon black using the impregnation and microwave irradiation methods. The prepared catalysts were characterized by XRD, TEM and EDX analyses. TEM images indicated that the microwave method provides homogeneously distributed catalyst particles in smaller size, compared to the one prepared by the impregnation method. The electrocatalytic activity of Pt-CuO/C electrocatalysts was investigated to oxidize methanol in 0.5 M H2SO4 solution by applying cyclic voltammetry and chronoamperometry techniques. The oxidation current density of Pt-CuO/C electrocatalyst, prepared by the microwave method, showed two folds increment with a potential shift in the negative direction by 69 and 36 mV at the first and second oxidation peaks, respectively, relative to those at the catalyst prepared by the impregnation method. The effect of varying methanol concentration on the resulting oxidation current density of Pt-CuO/C electrocatalysts was studied. Some kinetic information about the reaction order with respect to methanol and Tafel slope values was calculated. Slower current density decay was observed in the chronoamperogram of Pt-CuO/C electrocatalyst, prepared by the microwave method, reflecting a lower degree of surface poisoning. CopyrightInternational Journal of Hydrogen Energy 12/2012; 37(24):18870-18881. DOI:10.1016/j.ijhydene.2012.10.009 · 3.31 Impact Factor
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ABSTRACT: This article reviews the progress made in the past 5 years in the field of direct and non-enzymatic electrochemical sensing of glucose. Following a brief discussion of the merits and limitations of enzymatic glucose sensors, we discuss the history of unraveling the mechanism of direct oxidation of glucose and theories of non-enzymatic electrocatalysis. We then review non-enzymatic glucose electrodes based on the use of the metals platinum, gold, nickel, copper, of alloys and bimetals, of carbon materials (including graphene and graphene-based composites), and of metal-metal oxides and layered double hydroxides. This review contains more than 200 refs. Figure This article reviews the history of unraveling the mechanism of direct electrochemical glucose oxidation and the attempts to successfully develop non-enzymatic electrochemical glucose sensors over the past 5 years.Microchimica Acta 02/2012; 180(3-4). DOI:10.1007/s00604-012-0923-1 · 3.74 Impact Factor
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ABSTRACT: This review covers advances in electrochemical and biochemical sensor development and usage during 2010 and 2011. In choosing scholarly articles to contribute to this review, special emphasis was placed on work published in the areas of reference electrodes, potentiometric sensors, voltammetric sensors, amperometric sensors, biosensors, immunosensors, and mass sensors. In the past two years there have been a number of important papers, that do not fall into the general subsections contained within the larger sections. Such novel advances are very important for the field of electrochemical sensors as they open up new avenues and methods for future research. Each section above contains a subsection titled "Other Papers of Interest" that includes such articles and describes their importance to the field in general. For example, while most electrochemical techniques for sensing analytes of interest are based on the changes in potential or current, Shan et al.1 have developed a completely novel method for performing electrochemical measurements. In their work, they report a method for imaging local electrochemical current using the optical signal of the electrode surface generated from a surface plasmon resonance (SPR). The electrochemical current image is based on the fact that the current density can be easily calculated from the local SPR signal. The authors demonstrated this concept by imaging traces of TNT on a fingerprint on a gold substrate.Analytical Chemistry 11/2011; 84(2):685-707. DOI:10.1021/ac202878q · 5.64 Impact Factor