Biomedical Engineering Reference
In-Depth Information
1.8418 to 1.7642, and the binding rate coefficient
k
decreases by 31.2% from a value of 8.822
to 6.074. Note that changes in the fractal dimension
D
f
or the degree of heterogeneity on the
biosensor surface and in the binding rate coefficient are in the same direction.
Bromage et al. (2007)
have recently developed a real-time biosensor for the detection of trace
levels of TNT in aquatic environments. They report that most chemicals will have a
biological impact on aquatic species at concentrations too low to be visually observed
(
Anderson et al., 1997
). Hence the need to make rapid detection and quantitative trace con-
centrations of different chemicals. They focused on the detection of trace amounts of TNT in
aqueous environments as environmental contamination occurs particularly from military sites
due to manufacturing, storage, and handling of munitions. These authors further state that
TNT is known to accumulate in plants and fish (
Belden et al., 2005; Ownby et al., 2005
),
and have detrimental effects on fish (
Ek et al., 2005
), besides accumulating in aquatic
sediments (
Richter-Torres et al., 1995
). They have developed a highly sensitive TNT
immunosensor with a prototype fluorescence-based detector system (KinExA Inline Biosen-
sor, Sapidyne Instrument Inc.). The antibody that they used had a high affinity for TNT, and
a minimal cross reactivity for tetryl, 2,4-dinitrotoluene and 2-amino-4,6-dinitrotoluene. An
additional advantage was that the sensor could be regenerated within 8 min, and permitted
a minimum of 40 readings.
Figure 13.3a
shows the binding and dissociation of 0
m
g/L of TNT in the aqueous environ-
ment to anti-TNT mAb (anti-nitrophenol monoclonal antibody) by a highly sensitive TNT
immunosensor with a prototype fluorescence-based detection system (KinExA Inline Biosen-
sor, Sappidyne Instrument, Inc.;
Bromage et al., 2007
). A single-fractal analysis is adequate
to describe the binding and the dissociation kinetics. The values of (a) the binding rate coef-
ficient
k
and the fractal dimension
D
f
for a single-fractal analysis, and (b) the dissociation
rate coefficient
k
d
and the fractal dimension for dissociation
D
fd
are given in
Tables 13.3
and
13.4
.
Figure 13.3b
shows the binding and dissociation of 0.01
m
g/L of TNT in the aqueous environment
to anti-TNT mAb by a highly sensitive TNT immunosensor with a prototype fluorescence-based
detection system (KinExA Inline Biosensor, Sappidyne Instrument, Inc.;
Bromage et al., 2007
).
Once again, a single-fractal analysis is adequate to describe the binding and the dissociation
kinetics. The values of (a) the binding rate coefficient
k
and the fractal dimension
D
f
for a
single-fractal analysis, and (b) the dissociation rate coefficient
k
d
and the fractal dimension
for dissociation
D
fd
are given in
Tables 13.3
and
13.4
.
Figure 13.3c
shows the binding and dissociation of 0.05
m
g/L of TNT in the aqueous environment
to anti-TNT mAb by a highly sensitive TNT immunosensor with a prototype fluorescence-based
detection system (KinExA Inline Biosensor, Sappidyne Instrument, Inc.;
Bromage et al., 2007
).
Once again, a single-fractal analysis is adequate to describe the binding and the dissociation
kinetics. The values of (a) the binding rate coefficient
k
and the fractal dimension
D
f
for a
