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Amperometric sensor for nitrite using a glassy carbon electrode modified with thionine functionalized MWCNTs/Au nanorods/SDS nanohybrids
Author(s) -
Zhang Yu,
Yuan Ruo,
Chai Yaqin,
Zhong Xia,
Zhong Huaan
Publication year - 2012
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.4924
Subject(s) - nanorod , thionine , detection limit , electrode , carbon nanotube , nitrite , chemical engineering , sodium dodecyl sulfate , materials science , inorganic chemistry , adsorption , chemistry , electrochemistry , nanotechnology , chromatography , organic chemistry , engineering , nitrate
A sensitive nitrite (NO 2 ‐ ) biosensor was fabricated by using sodium dodecyl sulfate (SDS), Au nanorods, and thionine functionalized MWCNTs (TH‐f‐MWCNTs) nanohybrids modified glassy carbon electrode. TH was covalently immobilized on the MWCNTs via a carbodiimide reaction. Comparing with MWCNTs/GCE, TH‐f‐MWCNTs/GCE displays higher catalytic activity toward the oxidation of NO 2 ‐ , since TH not only promoted the electronic transmission but also could improve the concentration of NO 2 ‐ at the surface of the modified electrode in acidic solutions. The Au nanorods (AuNRs) were prepared through a simple wet chemical method and were characterized by TEM. The extremely high surface‐to‐volume ratios associated with one dimension nanostructures make their electrical properties extremely sensitive to species adsorbed on surfaces and result in excellent sensitivity and selectivity. SDS displays excellent film forming ability, which made the electrode stable. Under optimal conditions, the linear range for the detection of nitrite was 0.26 to 51 μM, and the low detection limit was 20 nM. In addition, the modified electrode was successfully applied to determine nitrite in real water samples. Copyright © 2012 John Wiley & Sons, Ltd.