Biomedical Engineering Reference
In-Depth Information
0.6
0.5
0.4
0.3
0.2
0.1
0
0
10
20
Time (min)
30
40
Figure 14.4
Binding of catechol to bentonite-vanadium (V) oxide xerogels (
Anaissi and Toma, 2005
). When
only a solid line (--) is used then a single-fractal analysis applies. When both a dashed (- - -) and a
solid (--) line are used then the dashed line represents a single-fractal analysis and the solid line
represents a dual-fractal analysis, and the dashed line represents the single-fractal analysis. In both
cases, the solid line is the best fit line.
10
5
mol/dm
3
) to the BV
(bentonite-vanadium (V) oxide xerogel) (
Anaissi and Toma, 2005
).
Table 14.3: Binding and intercalation of dilute catechol solution (7.8
Analyte in Solution /Receptor on
Surface
k
k
1
k
2
D
f
D
f1
D
f2
10
5
mol/dm
3
catechol/
BV optode
7.8
0.8128
0.05583
0.1767
1.9692
1.3862
2.4884
0.00258
0.0084
0.1174
0.0709
0.0894
0.0160
rate coefficient,
k
, and the fractal dimension,
D
f
, for a single-fractal analysis, and (b) the
binding rate coefficients,
k
1
and
k
2
, and the fractal dimensions,
D
f1
and
D
f2
, for a dual-fractal
analysis are given in
Table 14.3
.
It is of interest to note that as the fractal dimension or the degree of heterogeneity in the
bentonite-vanadium (V) oxide xerogel increases by a factor of 1.795 from a value of
D
f1
equal to 1.3862 to
D
f2
equal to 2.4844 the binding rate coefficient increases by a factor of
3.165 from a value of
k
1
equal to 0.05583 to
k
2
equal to 0.1767. The changes in the degree
of heterogeneity or the fractal dimension on the bentonite-vanadium (V) oxide xerogel
surface and in the binding rate coefficient are in the same direction.
Pokhrel et al. (2007)
indicate that solid-state sensors are very versatile and may be used to detect
a wide variety of gases, besides which they may be used for other applications. These authors
indicate that solid sate sensors are able to detect low ppm levels of gases, besides detecting
high levels of combustible gases (
Moos et al., 2003
).
Kanda and Maekawa (2005)
point
