Biomedical Engineering Reference
In-Depth Information
multi-functional biosensor will be able to provide all practice demands in
the respect of the screening of several objects on the number of biochemical
indexes. In medical diagnostics it may be used for the simultaneous detec-
tion of the glucose concentration and the anti-insulin Ab in patients with
diabetes as well as for the registration of others biochemical parameters.
13.5
Modeling Selective Sites and their Application in
the Sensory Technology
h e development of biosensors is limited by the accessibility of the suitable
biological material and its insui cient stability in solution under the inl u-
ence of high temperatures and some chemical reagents which decrease the
sensitivity and selectivity of such devices. To avoid these disadvantages it
was used two dif erent approaches: one of them connected with the cre-
ation of the selective sides by the special chemical way [52, 53]. It gives
possibility for formation of the special places on the solid phase which
content the optimal environment in relation to steric and other interac-
tions which can provide binding analyzed substances. Second one is based
on the application of chemically structures which have some selectivity to
analyzed substances. In both cases there is necessary to use a lot of such
semi-selective sites and to apply a special computer program for discrimi-
nation of non-selective bindings and revealing selective ones.
13.5.1
Template Sensor: Principle of Creation and
Characteristics of Work and Determination of Some
Biochemical Substances [52]
For the realization of this purpose the silicon plates were treated with hot
steam during 1 h. h en the plates were placed in a 5 mM solution of the
templates for 12 h. At er removing the excess solution the plates were dried
at 120
0
C for 3 h and placed in a vacuum l ask with 5 ml of frozen Me
3
SiCl
and kept at room temperature for 12 h. Finally, the templates were washed
from the plates with water and ethanol. As a control the samples modii ed
by silanes but without templates were used (Figure 13.9).
h e glass electrodes were modii ed with Me
3
SiCl as described above and
by ODSiCl
3
, as reported previously [53] in the presence of cholesterol and
without it (control samples). h e indium tin oxide (ITO) electrodes were
modii ed by Me
3
SiCl in the presence of phenylalanine. h e sorption of [P
32
]
ATP or amino acids was carried out on modii ed plates in the presence or
absence of template for 30 min. h en the plates were washed very carefully
