A parylene-protected nitrate selective microsensor on a carbon fiber cross section
This work describes a novel design for a potentiometric microsensor for nitrate (NO 3 −) ion based on doped polypyrrole (PPy(NO 3 −)) films. First, 6–7 μm diameter single carbon fiber filaments are coated with a thin (1–10 μm) insulating layer of parylene C (poly( o-chloro- p-xylylene)). This prepar...
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Published in | Sensors and actuators. B, Chemical Vol. 123; no. 1; pp. 127 - 134 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
Elsevier B.V
10.04.2007
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Subjects | |
Online Access | Get full text |
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Summary: | This work describes a novel design for a potentiometric microsensor for nitrate (NO
3
−) ion based on doped polypyrrole (PPy(NO
3
−)) films. First, 6–7
μm diameter single carbon fiber filaments are coated with a thin (1–10
μm) insulating layer of parylene C (poly(
o-chloro-
p-xylylene)). This preparatory step is followed by electrodeposition of a PPy(NO
3
−) sensing layer on the open carbon fiber cross section. Parylene C provides an excellent protective coating for the fiber while maintaining its flexibility at micro-dimensions. Examination by scanning electron microscopy confirms that the sensing material (PPy(NO
3
−)) is deposited in the form of micro-beads with diameter of 30–40
μm at the fiber tip. The resulting nitrate sensor exhibits an improvement of approximately half an order of magnitude of NO
3
− concentration in sensitivity and linear response range relative to a previously reported PPy(NO
3
−)-based sensor for which the sensing layer was deposited on the carbon fiber walls. The overall sensor geometry, a micro-dimensioned sensing portion accompanied by a flexible, parylene-insulated body, forms a sensor for nitrate with a unique form factor that can be widely used for
in situ measurements of variety of environmental samples. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 0925-4005 1873-3077 |
DOI: | 10.1016/j.snb.2006.08.007 |