文档介绍：Biosensors Based on Carbon Nanotubes
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Yuehe Lin
Wassana Yantasee
Fang Lu
Pacific Northwest National Laboratory, Richland, Washington, .
Joseph Wang
Mustafa Musameh
New Mexico State University, Las Cruces, New Mexico, .
Yi Tu
Zhifeng Ren
Boston College, Chestnut Hill, Massachusetts, .
INTRODUCTION were first introduced in 1991.[22] CNTs are distinguished
according to their structural properties:[23] a single-wall
Carbon nanotube (CNT) is an attractive material for T (T) consists of a single graphitic sheet rolled
development of biosensors because of its capability to into a cylinder (with 1 to 2 nm . and several microns in
provide strong electrocatalytic activity and minimize length), and T (T) consists of
surface fouling of the sensors. This article reviews the graphitic sheets rolled into closed concentric tubes (with
recent essful development of biosensors based on 50 nm . and microns in length), each separated by van
CNT materials. Specifically, biosensors from two fabri- der Waals forces to have a gap of A˚. Carbon nanotubes
cation regimes have been investigated: 1) the coimmobi- have been known to promote electron-transfer reactions
lization Ts and enzymes on electrode surfaces and of cytochrome c,[2] NADH,[1,6] catecholamine neuro-
2) the growth of controlled-density Ts for the transmitters,[3] and ascorbic acid.[4] This is attributed to
fabrication of nanoelectrode arrays. In the first regime, the their electronic structure, high electrical conductivity, and
CNTs are either dispersed in solvents [., sulfuric acid, redox active sites. Carbon is also a versatile electrode mate-
dimethylformamide (DMF)], dissolved in Nafion solution rial that can undergo various chemical and electrochemical
for electrode coating, or mixed with Teflon as an electrode modifications to produce suitable surfaces for high elec-
material for reagentless biosensors. In the second regime, trode responses. Carbon electrodes have a