Biomedical Engineering Reference
In-Depth Information
tal data transfer,the analysis is protected against interference such as that cau-
sed by voltage spikes.
Although exhausted enzymes can be replaced quickly, the compact device
does not solve the problems of enzyme instability or complex thermostating.Its
construction is more practically orientated.The major aim of the study was the
transformation of an ET into a more practical useful arrangement.
6
Conclusions
In summary,thermal biosensors are still attracting great interest in several areas
of biotechnology due to their wide applications. They will surely not solve all
bioanalytical problems. In particular, the TELISA systems are in strong com-
petition with the better working fluorescence assays.Of course,this is not just a
reason of the transducer technique but depends on the necessary and expensive
conjugate preparations. Nevertheless, in special areas thermal biosensors still
have superior characteristics in comparison to other transducer types. When
miniaturized,they might be very interesting for clinical glucose monitoring due
to their functioning without interference from ascorbic acid.The latter is a big
problem for amperometric transducers. Thermal biosensors give their best
results with deaminating (e.g., urease, glutaminase, asparaginase) and hydro-
lytic enzymes (e.g.,
-chymotrypsin, pig liver esterase). Since the 1990s, new
applications for the ET have been investigated and have enlarged the possibil-
ities of biosensor application. If one summarizes the experiences of the last
twenty years,the ET seems to be a very interesting tool for learning basic prin-
ciples and setting trends in biosensorics.
As mentioned above, miniaturization is not required for bioprocess moni-
toring. However, the experiences with microcontrollers and constructions of
practically useful arrangements might be very efficient in combination with
the miniaturized ET and thermopiles developed so far. The construction of
devices which are simple to operate should be the target and trend for the next
years.The technical prerequisites are:compact boxes containing the whole mea-
suring electronics and the sensor chips with immobilized enzymes that are easy
to exchange after exhaustion.In this case,thermal biosensors will have a good
chance in biotechnology.However,each analysis problem probably has its own
characteristics and several (bio)sensor types should carefully considered.
a
7
References
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pasteurization of milk with H
2
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Alonso A,Almendral MJ,Baez MD,Porras MJ,Alonso C (1995)Enzyme immobilization on an
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308:164-169
Amici AM,Minghetti A,Scotti T,Spalla C,Tognolli L (1967) Ergotamine production in sub-
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