Carbon fiber microelectrodes

N.R. Ferreira, A. Ledo, J.G. Frade, G.A. Gerhardt, J. Laranjinha, and R.M. Barbosa, Electrochemical measurement of endogenously produced nitric oxide in brain slices using Nafion/o-phenylenediamine modified carbon fiber microelectrodes. Anal. Chim. Acta 535, 1—7 (2005). 

J. Katrlik and P. Zalesakova, Nitric oxide determination by amperometric carbon fiber microelectrode. Bioelectrochemistry 56, 73-76 (2002). 

To fulfill both the requirement of CFME for the practical applications and the necessity of Au substrate to assemble so-called promoters to construct the third-generation biosensor, Tian el al. have combined the electrochemical deposition of Au nanoparticles (Au-NPs) onto carbon fiber microelectrodes with the self-assembly of a monolayer on these Au-NPs to facilitate the direct electron transfer of SOD at the carbon fiber microelectrode. The strategy enabled a third-generation amperometric 02 biosensor to be readily fabricated on the carbon fiber microelectrode. This CFME-based biosensor is envisaged to have great potential for (he detection of 02" in biological systems [158],... 

SCHEME 4 (a) Carbon fiber microelectrode, and (b) the process of electrode modification. (Reprinted from [158], with permission from Elsevier.)... 

The Au-NPs were electrodeposited on the carbon fiber microelectrodes from 0.5 M H2S04 solution containing l.OmM Na AuCl4] by applying a potential step from 1.1 V to 0V for 30 s. Cysteine-modified Au-NPs-electrodeposited CFMEs were prepared by... 

Y. Tian, L. Mao, T. Okajima, and T. Ohsaka, A carbon fiber microelectrode-based third-generation biosensor for superoxide anion. Biosens. Bioelectron. 21, 557-564 (2005). 

L. Mao, J. Jin, L. Song, K. Yamamoto, and L. Jin, Electrochemical microsensor for in vivo measurements of oxygen based on Nafion and methylviologen modified carbon fiber microelectrode. Electroanalysis. 11, 499-504 (1999). 

Y. Wang, J. Huang, C. Zhang, J. Wei, and X. Zhou, Determination of hydrogen peroxide in rainwater by using a polyaniline film and platinum particles co-modified carbon fiber microelectrode. 

W.B. Nowall and W.G. Kuhr, Detection of hydrogen peroxide and other molecules of biological importance at an electrocatalytic surface on a carbon fiber microelectrode. Electroanalysis 9, 102-109 (1997). 

M.F. Suaud-Chagny and F.G. Gonon, Immobilization of lactate dehydrogenase on a pyrolytic carbon fiber microelectrode. Anal. Chem. 58, 412—415 (1986). 

Figure 3.5 Scanning electron microscope images of the surfaces of (a) a bare carbon fiber microelectrode and (b) a multiwalled carbon nanotube -[C4CjIm][PF ]-modified carbon fiber microelectrode. (Reprinted from Liu, Y., Zou, X., and Dong, S., Electrochem. Commun., 8,1429-1434,2006. Copyright 2006 Elsevier. With permission.)...

Ciolowski EL, Maness KM, Cahill PS, Wightman RM, Evans DH, Posset B, Amatore C (1994) Disproportionation during electrooxidation of catecholamines at carbon-fiber microelectrodes. Anal Chem 66 3611-3617. 

D.D. Kindler, C. Thiffault, N.J. Solenski, J. Dennis, V. Kostecki, R. Jenkins, P.M. Keeney and J.P.Rr. Bennett, Neurotoxic nitric oxide rapidly depolarizes and permeabilizes mitochondria by dynamically opening the mitochondrial transition pore, Mol. Cell. Neurosci., 23 (2003) 559-573. N.R. Ferreira, A. Ledo, J.G. Frade, G.A. Gerhardt, J. Laranjinha and R.M. Barbosa, Electrochemical measurement of endogenously produced nitric oxide in brain slices using Nafion/o-phenylenediamine modified carbon fiber microelectrodes, Anal. Chim. Acta, 535 (2005) 1-7. 

E. Csoregi, L. Gorton, G. Marko-Varga, A.J. Tudos and W.T. Kok, Peroxidase-modified carbon fiber microelectrodes in flow-through detection of hydrogen peroxide and organic peroxides, Anal. Chem., 66 (1994) 3604. 

It is also possible to employ detectors with solutions flowing over a static mercury drop electrode or a carbon fiber microelectrode, or to use flow-through electrodes, with the electrode simply an open tube or porous matrix. The latter can offer complete electrolysis, namely, coulometric detection. The extremely small dimensions of ultramicroelectrodes (discussed in Section 4.5.4) offer the advantages of flow-rate independence (and hence a low noise level) and operation in nonconductive mobile phases (such as those of normal-phase chromatography or supercritical fluid chromatography). 

Fig. 14.34. Voltammetry of epinephrine. Background (A, solid line) and signal containing (A, dashed line) currents generated during fast-scan cyclic voltammetry (300 V/s) at a carbon fiber microelectrode r = 5 pm). A background subtracted cyclic voltammogram (B) is produced from the traces shown in A. (Reprinted from Wightman, et al. Chemical Communication, Interface, 5(3) 22, Fig. 2,1996. Reproduced by permission of the Electrochemical Society, Inc.)...

Electrode surface activation can be improved simply by electrochemical pretreatment. Determination of nitroaromatic compounds in water and soil spiked samples have been reported at electrochemically activated carbon-fiber microelectrodes. No interference was found from compounds such as hydrazine, phenolic compounds, carbamates, triazines or surfactants. The detection limit obtained can be approximately 0.03 iigml-1 for all the nitroaromatic compounds (Agui et al. 2005). Chen and coworkers reported an effective field-deployable tool for detecting nitroaromatic compounds with an electrochemically pre-anodized screen-printed carbon electrode (SPE) (Chen et al. 2006). 

Gerhardt GA, Hoffman AF (2001) Effects of recording media composition on the responses of Nafion-coated carbon fiber microelectrodes measured using high-speed chronoamperometry. J Neurosci Methods 709(1) 13-21. 

Garris PA, Ensman R, Poehhnan J, Alexander A, Langley PE, Sandberg SG, Greco PG, Wightman RM, Rebec GV. Wireless transmission of fast-scan cyclic voltammetry at a carbon-fiber microelectrode proof of principle. J. Neurosci. Methods. 2004 140 103-115. 

The first carbon fiber microelectrode reported in literature was that fabricated by Ponchon and co-workers in 1979[18], This procedure involved pulling a glass tube to obtain a diameter of few micrometers. Then the carbon fiber (outside diameter 8 pm, length 20 to 40 mm) was threaded into the capillary, thus enabling the fiber to be pushed a few mm through the capillary. The authors reported that this method minimized the interstitial space between the capillary and the carbon fiber. Then, the capillary was inverted into a mixture of graphite powder and polyester resin to fill 4-5 mm of the body with the paste. A contact wire was then pushed as far as possible into the barrel filled with the paste. Immediately before use, the electrodes were cut to a length of 0.5 mm[18]. 

Figure 23-29 Optical image using brightfield microscopy showing a carbon fiber microelectrode adjacent to a bovine chromaffin cell from the adrenal medulla. The extracellular solution was 10 mM TRIS buffer containing 150 rnM NaCl, 2 mM CaCfi, 1.2 mM MgCfi, and 5 mM glucose. The black scale bar is 50 p.m. (From L. Buhler and R. M. Wightman, unpublished work. With permission.)...

Suaud-Chagny and Goup (1986) immobilized LDH on a pyrolytic carbon fiber microelectrode by impregnation in an inert protein sheath that was first electrochemically deposited around the active tip of the electrode. The NADH detection was improved by electrochemical treatment of the electrode. The detection limit for pyruvate was lower than 1 pmolA. The sensor was used to estimate pyruvate concentration in rat cerebrospinal fluid. 

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