Biomedical Engineering Reference
In-Depth Information
Table 9.7
(
Continued
).
Target
analyte
Transducer
Materials/methods
Main performance
Ref.
QCM
10 MHz
SWCNT LB multilayered
film
Toluene,
m-Xylene
CR: 10-50 ppm Toluene
S: 1-2 Hz/ppm
DL: 0.5 ppm Toluene
Rst: 4-7 min; Rct: 4-9 min
OT: RT
RH interference study
[298]
QCM
10 MHz
SWCNT LB film
multilayer onto CdA
Alcohols
S: 230 Hz/59 mmHg Ethanol
OT: RT; Rst: <2 min
[153]
QCM
10 MHz
SWCNT/CdA
nanocomposite LB film
VOCs
CR: 10-200 mmHg Alcohols
CR: 100-650 mmHg Ketones
CR: 30-270 mmHg Esters
CR: 10-110 mmHg Aromatics
OT: RT; Rst: <2 min
[37]
QCM
10 MHz
SWCNT LB film
Aromatics CR: 0-100 ppm Toluene
CR: 0-40 ppm m-Xylene
S: 0.9 Hz/ppm Toluene
S: 1.8 Hz/ppm m-Xylene
Rst: <10 min; Rct: <15 min
OT: RT;
[294]
QCM
9 MHz
HiPco SWCNT bundles
N
, O
, Ar
Gas adsorption isotherms
[295]
2
2
QCM
9 MHz
MWCNT/Nafion
composite
RH
CR: 0-1% RH
S: 3.5 Hz/ppm at 23.4 ppm
Linearity (
[194]
R
2
= 0.9604)
Rst: <30 sec
QCM
10 MHz
Pd-modified
MWCNT-COOH films
RH
CR: 0.2-1% RH
S: 0.05 Hz/ppm
Linearity (
[296]
2
R
= 0.9663)
TFBAR
1.045 GHz
SWCNT/CdA
nanocomposite LB film
at 75 wt.% filler content
VOCs
CR: 165-500 ppm Acetone
CR: 90-330 ppm Ethylacetate
S: 12 kHz/ppm Acetone
S: 17.3 kHz/ppm Ethylacetate
DL: 12.5 ppm Acetone
DL: 8.7 ppm Ethylacetate
Rst: 2-3 min; Rct: <60 min
OT: RT
[292]
DL = detection limit; S = sensitivity; SSAW = sensitivity of SAW sensor; SQCM = sensitivity
of QCM sensor; CR = concentration range; Rst = response time; Rct = recovery time; OT =
operating temperature; LIN = linearity range.
9.5.5
Other Transducers
Here, the other principal transducers for gas sensors based on CNTs
layers will be reviewed by describing the main technical performance
in chemical detection.
. [299] demonstrated the use of SWCNTs as
a chemicapacitors for sensing of both polar and nonpolar gas
molecules at room temperature. The SWCNT-based chemicapacitors
were fabricated by a CVD-grown SWCNT networks on a 250-nm
E. S. Snow
et al
