Biomedical Engineering Reference
In-Depth Information
One of the distinct advantages of biosensors is the continuous real-time monitoring at close
proximity. Thus, this is very suitable for health-care applications such as patient monitoring.
Other applications could also include monitoring of industrial operations and of exposure of
humans to chemical and biological hazards, especially under warfare conditions. Biosensors
are successful in economically monitoring health care due to the large number of patients, for
example, blood glucose monitoring for diabetics or prediabetics. However, the volume of
“target applications” severely constrains the applications of biosensors especially for non-
health applications, where the volume of targets is relatively small. One is thus unable to off-
set the large expense and time required (to bring the biosensor from the bench to the market)
to develop the biosensor for a specific analyte. In general, there should be either an order of
magnitude increase in the number of targets or an order of magnitude decrease in the devel-
opment cost and time to market. This time to market is also of importance, owing to intense
competition. Another way, for biosensors to provide a reasonable ROI, is if one is able to find
a high-end market application, as indicated earlier, for the biosensor with a reasonable
number of possible targets.
Because a biosensor traditionally involves converting a biological or chemical signal to an
electrical signal (output), in other words, a transduction, expertise in both areas is essential,
as otherwise this can very significantly affect the efficiency of the biosensor. This increases
the expense of the biosensor development. Other cost sensitive parts in biosensor develop-
ment is the fabrication of biosensors in bulk, and the constraints of single-use or at best using
a biosensor for a few times only. This is owing to contamination and reproducibility issues.
Hence, the emphasis on “disposable” type biosensors; but again these, by their very nature,
need to be inexpensive.
Biosensors have different inherent performance parameters such as sensitivity, selectivity,
response time, simplicity (ease of use), reproducibility, robustness, detection time, and detec-
tion limits. To economically justify the use of biosensors for different and varying
applications, it is necessary to clearly justify the substantial improvement or enhancement
of one (or preferably more) of the above mentioned performance parameters over other con-
ventional means of detection. This is especially true if it is not possible to justify the use of
one method of detection over the other strictly on an economic basis. All of this points to the
formation of carefully-thought out partnerships wherein different and synergistic strengths
may be brought to the table, keeping in mind at all times, that the market is not very large,
and any failure should ensure that the loss is not overly unbearable. More often than not rea-
sonable investment sources are required, keeping in mind that it will be close to 10 years
before any sort of reasonable profit may be made from these biosensor devices. It is there-
fore, not surprising that big companies with deep pockets have dominated the biosensor mar-
ket. This is amply demonstrated by the acquisition of Biacore by General Electric a few years
ago. It must be remembered that Biacore in Sweden developed and marketed the first
operating surface plasmon resonance (SPR) biosensor.
