Nano Archive

Increasing amperometric biosensor sensitivity by length fractionated single-walled carbon nanotubes

Tasca, Federico and Gorton, Lo and Wagner, Jakob B. and Noll, Gilbert (2008) Increasing amperometric biosensor sensitivity by length fractionated single-walled carbon nanotubes. BIOSENSORS & BIOELECTRONICS, 24 (2). pp. 272-278.

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In this work the sensitivity-increasing effect of single-walled carbon nanotubes (SWCNTs) in amperometric biosensors, depending on their average length distribution, was studied. For this purpose the SWCNTs were oxidatively shortened and subsequently length separated by size exclusion chromatography. Transmission electron micrographs of different fractions of SWCNTs were collected. Diaphorase ``wired'' to an osmium redox polymer was blended with the shortened SWCNTs of different lengths. Depending on the average length of the SWCNTs the sensitivity of the amperometric biosensor model system towards oxidation of 1.4-dihydronicotinamide adenine dinucleotide (NADH) was increased by a factor of five. The best performance was achieved with SWCNTs of medium length. The linear range for NADH detection was between 5 mu M and 7 mM, the maximum sensitivity was 47 nA mu M-1 cm(-2), and the detection limit was 1 mu M. The biosensor exhibited excellent electrocatalytic properties. Even at relatively high NADH concentrations the oxidative current was limited by the diffusion rate of NADH. (C) 2008 Elsevier B.V. All rights reserved.

Item Type:Article
Uncontrolled Keywords:amperometric biosensor; diaphorase NADH oxidation; osmium redox polymer hydrogel; length-separated single-walled carbon; nanotubes (SWCNTs); transmission electron microscopy (TEM)
Subjects:Analytical Science > Nanotechnology for sensing and actuating
Physical Science > Nano objects
Material Science > Nanochemistry
ID Code:1315
Deposited By:Anuj Seth
Deposited On:09 Dec 2008 17:40
Last Modified:20 Jan 2009 09:39

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