Biomedical Engineering Reference
In-Depth Information
sensitivity for Pt-modified CNT sensor able to detect 100 ppb NO
.
2
This limit represents the actual NO
attention level for environmental
monitoring in the Italian regulations. The resistance change induced
by 100 ppb NO
2
in the Pt-modified CNT sensor is extremely high as
2
5.1 k
Ω
and is higher than that of about 4
Ω
reported in literature
[27] for unmodified CNT-based NO
gas sensors. These results able
the metal-functionalized CNT gas sensors for environmental air
monitoring applications.
2
Figure 9.32
(
) Schematic view of two-pole chemiresitor based
on MWCNT films functionalized with Pt-, Ru-, and Ag-clusters.
(
Top-left
) (
a
) SEM image
of vertically-aligned MWCNTs grown by Fe-catalyst PECVD.
(
b
) Image of four CNT chemiresistors. (
Top-right
Down-left
) Response to 1% H
, 0.7% CH
, 0.2% CO
, 0.1%
2
4
2
CO, 0.1% NH
of a four-sensor array based
on unmodified CNTs, and Ru-, Pt-, and Ag-modified MWCNTs
vertically-aligned
, and 10 ppm NO
3
2
forest-like
networks, at 152°C. (
Down-
right
) Response of a four-sensor array to a multicomponent
gas mixture of landfill gas with various content of the target
NO
gas (3.3 ppm to 330 ppb) by unmodified and metal-
functionalized CNT. The sensor temperature is 152°C. The
gas mixture B of the landfill gas is composed of 550 ppm
CO
2
in air.
This figure is reprinted and adapted with permission from
IOP [36].
, 660 ppm H
, 460 ppm CH
, and 260 ppm NH
2
2
4
3
