Biomedical Engineering Reference
In-Depth Information
Table 15.3: Binding and dissociation rate coefficients for the PSA protein biomarker on different
gold nanocrystals for immunoprobe concentrations in solution (
Cao et al., 2009
).
PSA
Concentration
(M)
k
k
1
k
2
k
d
10
7
0.65
0.000077
0.000037 0.000182
0.000077 0.01948
0.00188
na
10
7
1.3
0.005087
0.002666 0.000834
0.000153 0.1692
0.0077
na
10
7
5.2
0.1825
0.030
na
na
0.004847
0.000380
Table 15.4: Fractal dimensions for the binding and dissociation phase for PSA protein biomarker
on different gold nanocrystals immunoprobe concentrations in solution (
Cao et al., 2009
).
PSA Concentration
(M)
D
f
D
f1
D
f2
D
fd
10
7
0.65
0
þ
0.3478
0
þ
0.8996
1.8470
0.3568
na
10
7
1.3
0.496
0.03724
0
þ
0.3224
2.4488
0.1253
na
5.2 10
7
1.7042 0.2224
na
na
1.7042 0.8666
k
1
and
k
2
and the fractal dimensions
D
f1
and
D
f2
for a dual-fractal analysis are given in
Tables 15.3 and 15.4
.
Huber et al. (2006)
have recently used cantilever microarray technology to analyze the bind-
ing of two different DNA-binding proteins, the transcription factors SP1 and NF-
k
B. Their
use of cantilever arrays permits them to use label-free measurement of different biomolecular
interactions in parallel. They took double-stranded DNA oligonucleotides containing a spe-
cific binding site for a transcription factor and these were sensitized on gold-coated can-
tilevers. The binding of the transcription factor created a surface stress. This surface stress
resulted in a bending of the cantilevers.
Huber et al. (2006)
report that cells respond to changes in the environment by regulating gene
expression.
Honore et al. (2004)
have specified the different technologies that have been used
to study this, such as DNA microarrays, 2D electrophoresis of proteins, and ELISA.
Huber
et al. (2006)
have proposed microcantilever array technology to analyze gene regulation
not only at the mRNA or protein level but also at the level of transcription factors. They
report that microcantilver arrays have been used to analyze DNA hybridization (
Fritz
et al., 2000; McEndry et al., 2004
), and antigen-antibody interaction (Wu et al., 2001;
Arntz
et al., 2003
). They coated one side of the microfabricated silicon cantilevers with gold. This
permitted the sensitization of the thiol-modified receptor molecules (DNA oligonucleotides
or antibodies).
