Biomedical Engineering Reference
In-Depth Information
Table 7.1
Enzymes assayed in medical diagnostics.
Enzyme
Used in determination of
Lactate dehydrogenase (LDH)
skeletal muscle or heart damage
Alkaline phosphatise
Liver and bone disease
Serum glutamate oxaloacetate
transaminase (SGOT)
Liver and heart disease
Creatine phosphokinase (CK)
Muscle and myocardial infarction
disease
Acid phosphatase
Cancer of the prostate
α-Amylase
pancreatitis
7.6 Biosensor
A biosensor is described as a compact, composed analytical device, sys-
tematically incorporating a biological or biometric sensing element or sub-
stance, either closely connected to, or integrated highly within a transducer
system in Figure 7.3. h e principle of detection is the specii c binding and
ligands formation of the analyte which is of interest to the complimentary
bio recognition element immobilised on a suitable support medium or
condition for development. h e specii c interaction and co-relation results
in a change in one or more physico-chemical properties such as heat trans-
fer, uptake or release of gases, pH change, electron transfer, mass change or
specii c ions which are been detected, investigated and may be measured
by the transducer system. h e usual and specii ed aim and objective is to
produce an electronic signal which is directly proportional in magnitude
or frequency to the concentration of a specii c analyte or group of analytes
to which the bio sensing element binds enormously [29, 30].
h e history of biosensor began very early with glucose monitor-
ing, dated as far as 1956 through the prominent and amazing work of
Professor Leland C. Clark. He used an enzyme as called glucose oxidase
in a dialysis membrane over an oxygen probe and i nally the device was
called as enzyme electrode [31]. h e determination of glucose was done
by enzyme electrode. Updike
et al.
[32] developed a specii c enzyme by
using electrochemical procedure to design a well equipped model that
uses glucose oxidase immobilised on a gel for measuring and identifying
the concentration of glucose in biological solutions and in the tissues
