Carbon Nanotube Fiber Microelectrodes

Wang, Joseph; Deo, Randhir P.; Poulin, Philippe; Mangey, Maryse

doi:10.1021/ja037737j

Cited by 183 publications

(121 citation statements)

References 17 publications

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“…4 Much effort was devoted to pursuing new electrode materials and methods to decrease the detection potential and to avoid electrode surface fouling. One of the recently emerged and efficient ways to circumvent a high overpotential for the oxidation of NADH was to use carbon nanotubes (CNTs), since CNTs could significantly reduce the NADH overpotential, [5][6][7][8][9][10] although the decrease was not adequate.…”

Section: Introductionmentioning

confidence: 99%

Low-Potential Nicotinamide Adenine Dinucleotide Detection at a Glassy Carbon Electrode Modified with Toluidine Blue O Functionalized Multiwall Carbon Nanotubes

et al. 2006

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The determination of β-nicotinamide adenine dinucleotide (NADH) is very important, because the NAD + /NADH couple is a cofactor system for a large number of dehydrogenase enzymes (>300) and a component of biomarker systems.1 However, the direct oxidation of NADH at a bare electrode surface is highly irreversible, and needs a considerable overpotential (>1 V), 2,3 which is increased further by the presence of an enzyme. One of the most serious problems resulting from a high overpotential detection is fouling of the electrode surface associated with the accumulation of reaction products. 4 Much effort was devoted to pursuing new electrode materials and methods to decrease the detection potential and to avoid electrode surface fouling. One of the recently emerged and efficient ways to circumvent a high overpotential for the oxidation of NADH was to use carbon nanotubes (CNTs), since CNTs could significantly reduce the NADH overpotential, 5-10 although the decrease was not adequate.Another conventional approach to lower the oxidation potential of NADH is to apply redox mediators with low formal potentials. 11 Phenothiazine derivatives, such as azure (AZU) dyes, were usually utilized in this respect, because they are chemically reactive and display negative formal potentials (vs. SCE) at neutral pH. NADH detectors were developed based on AZU dyes that have been either adsorbed, 12 electropolymerized 13,14 or covalently attached 15 to the electrode surface. However, such modified surfaces displayed a rather limited stable ability and redox mediation capacity. The integration of phenothiazine derivatives and MWNTs in a polymeric matrix 16,17 for the determination of NADH with enhanced electrocatalytic characteristics was also reported, but the reported method was somewhat complicated. Hence, pursuing a simpler approach and new electrode materials to further decrease the overpotential for NADH oxidation and to minimize surface passivation effects to improve the detection sensitivity and redox mediation capacity is still an obvious challenge.In recent years, increasing interests have been focused on the rational functionalization of CNTs to fabricate functional nanostructures with novel properties. Some creative methods were used for the functionalization of CNTs with polymers, 18,19 biomolecules, 20,21 metal nanoparticles 22,23 and polynuclear aromatic compounds 24,25 through a covalent or noncovalent interaction. These functionalization strategies have generated many new materials with excellent functions, which are very attractive for practical applications. 26,27We describe here a simple method for constructing a new electrochemical functional nanostructure of TBO-MWNTs, which is based on a redox mediator, TBO assembled onto the surface of a MWNTs modified glassy carbon electrode. In this case the MWNTs act as a support of the redox mediator as well as a catalyst. The experimental results showed that the TBOMWNTs modified GC electrodes exhibited excellent electrocatalytic activity toward the oxidation of NADH. To the...

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Section: Introductionmentioning

confidence: 99%

Low-Potential Nicotinamide Adenine Dinucleotide Detection at a Glassy Carbon Electrode Modified with Toluidine Blue O Functionalized Multiwall Carbon Nanotubes

et al. 2006

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“…[4][5][6][7][8][9] Electrodes modified with CNT and used to analyze biomolecules have received much interest. [10][11][12][13][14][15][16][17][18] However, no preparation of electrodes modified by nano metal particlesdecorated carbon nanotubes has been reported. In our research, a glassy carbon electrode modified with platinum nano particles decorated on carbon nanotubes (Pt-CNT/GCE) was developed.…”

mentioning

confidence: 99%

Electrocatalytic Oxidation of Hydrogen Peroxide and Cysteine at a Glassy Carbon Electrode Modified with Platinum Nanoparticle-deposited Carbon Nanotubes

Tian

2005

ANAL. SCI.

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Dispersed metal particles exhibit excellent catalytic activity that closely relates to their minimized diameters. The micro and nano particles trend to have excellent quality in chemical and electrochemical reactions. For this purpose, metal particles have been successfully dispersed and decorated on some substrates such as carbon and conductive polymers to make catalyst. [1][2][3] It is essential to find ways to further reduce diameters of these metal particles to promote their catalytic activity. The diameters of nano particles vary with the medium and the substrates on which they are made. As one typical nano material, carbon nanotubes (CNT) whose diameters vary from 0.33 to less than 100 nanometers were made up with hexagonal lattices of carbon. Because of their characteristic electron conductivity valves, pore structures and absorption abilities they are fit for metal substrates. Various metals and alloys were deposited on them. [4][5][6][7][8][9] Electrodes modified with CNT and used to analyze biomolecules have received much interest. [10][11][12][13][14][15][16][17][18] However, no preparation of electrodes modified by nano metal particlesdecorated carbon nanotubes has been reported. In our research, a glassy carbon electrode modified with platinum nano particles decorated on carbon nanotubes (Pt-CNT/GCE) was developed. Carbon nanotubes decorated with platinum nano particles (Pt-CNT) were obtained by chemical method, 19 and then were immobilized on the surfaces of GCE electrodes. Electrochemical determinations using metals particle-modified electrodes have been focused on. [20][21][22][23][24][25][26][27] On the other hand, it is also important to prepare an amperometric sensor for the measurement of hydrogen peroxide and cysteine. 28 In the paper, electrocatalytic oxidation for hydrogen peroxide and cysteine at Pt-CNT/GCE was investigated. Due to the nano-sized platinum particles deposited on CNT, the currents at Pt-CNT/GCE were almost 3-times higher and the electrode reaction rates were obviously faster, compared with bare platinum electrode results. So, the Pt-CNT/GCE has high electro-catalytic activity, which is suitable for preparing enzyme electrodes with better sensitivity, repeatability and stability. Experimental Equipment and reagentsElectrochemical experiments were carried out using a CHI660B electrochemical workstation (CHI Instruments Inc., US). A glassy carbon electrode (φ = 2 mm) modified with Pt-CNT was used as the working electrode. A platinum wire and KCl saturated Ag/AgCl electrodes were employed as the counter electrode and a reference electrode, respectively. For comparison of the electro-catalytic activities, a bare Pt electrode (φ = 2 mm) was also used as a working electrode.Carbon nanotubes (inner φ = 4 -8 nm, outer φ = 10 -30 nm) were supplied by the Dept. of Materials, Zhejiang University; they were synthesized by Chemical Vapor Deposit method. 0.1 mol/L phosphate buffer solution (pH 7.0) was prepared by freshly distilled water. 10 mg/mL H2PtCl6 was made in 6 mol/L HCl solutions...

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“…CNTs have been devoted to decreasing the high overpotential for NADH oxidation on carbon paste electrodes (Blackburn,R.S. & Burkinshaw,S.M 2007) and microelectrodes (Wang, Deo, Poulin, & Mangey, 2003). By integrating the hydrophilic ion-conducting matrix of CHITn with electron mediator toluidine blue O and CNTs, the produced NADH sensor shows very low oxidation overpotential and good analytical performance (Zhang & Gorski, 2005).…”

Section: Nadhmentioning

confidence: 99%