Biomedical Engineering Reference
In-Depth Information
. [302] demonstrated an optical fiber sensor coated
by LB film of SWCNT networks for hydrogen detection at cryogenic
temperatures of 113 K. The optical probes were realized by the LB
deposition technique of close-end and open-end SWCNTs on the
distal end of the standard silica optical fibers. The results achieved
from hydrogen detection testing, carried out at a temperature as low
as 113 K, demonstrated the excellent potentiality of the proposed
configuration to detect very low percentages of gaseous hydrogen
below the explosion level in air (<5%), with fast response (4-5 min),
good recovery (8-11 min) and reversibility. As follow-up work, the
same team, see Consales
A. Cusano
et al
l
=
1310 nm) sensor based on SWCNT LB film for detection of aromatic
compounds of toluene and m-xylene at room temperature in the
gas concentration range from 5 to 90 ppm, with good sensitivity
(3.5
et al
. [303], developed an optical fiber (
−4
−4
/ppm for toluene and m-xylene,
respectively), response time (<8 min) and recovery time (<10 min).
Also, Consales
×
10
/ppm and 8.3
×
10
. [304] developed an optical fiber coated by
SWCNT LB films at the distal end for detection of toluene (20-80
ppm) in water environment. The good stability, high sensitivity (1.2
×
et al
−4
/ppm), detection limit as low as 5 ppm, good dynamics in the
response and recovery (few minutes) confirmed the potentiality
of this optical device for detecting chemicals in aqueous solutions.
Additionally, a new optochemical sensor based on hollow-core optical
fibers (HOFs) coated by SWCNT LB films at one terminal section was
developed as proof-of-concept by Cusano
10
. [305] and reflectance
(R) characterized in the range of wavelength from 1520 to 1620
nm. The sensing capability of HOF sensor was demonstrated for
chemical detection of tetrahydrofuran in the range of 180-300 ppm
in air showing a good sensitivity [(1/
et al
/ppm)],
a detection limit as low as 40 ppm, a response time (<15 min), and
recovery time (<30 min).
c
)(
∆
R
/
R
) = 4.6
×
10
−6
. [306] presented an infrared (IR) optical
absorbance study of highly uniform CNTs grown by CVD in a self-
assembled porous matrix of alumina. The IR spectral measurements
revealed that the CNTs were semiconducting with a band gap of
about 100 meV. This suggested the potential of CNTs arrays for IR
electro-optical sensing device applications.
N. Kouklin
et al
. [307] demonstrated molecular detection using
near-infrared light between 0.9 and 1.3 eV of interest for biomedical
applications by SWCNTs having a tunable near-infrared emission.
Barone
et al
