Biomedical Engineering Reference
In-Depth Information
Immobilisation
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Biosenser
Figure 7.3
A schematic representation of a biosensor adapted from Ref. [29].
in vitro
. h e term biosensor has eventually emerged from bio selective
sensor [33].
Biosensors are classii ed on the basis of bio receptor, transduction meth-
ods, and sometimes the bio-recognition principle. Bio-receptor provides
the key factor to specii city for biosensor technology today. h ey are highly
responsible for the bio-recognition event which may include reduction of
the substrate or catalytic oxidation that leaded to or binding of the analyte
of interest by the biosensor for the measurement. h e common bio-recep-
tors used are enzymes [34-38], antibody [39, 40], DNA [41, 42], whole
cell [43], and of recent aptamers in biosensor. Transduction methods used
in biosensor includes the following surface plasma resonance (SPR), elec-
trochemical, thermal, piezoelectric, optical, Quartz crystal microbalance
(QCM) [44] and cantilever [45-47]. Electrochemical method of transduc-
tion constitutes and comprises more than half of the literature portion on
biosensor [33].
h e two broad classii cation of biosensors based on bio-recognition
principle are ai nity biosensors typical of antibody or DNA and cata-
lytic biosensors typically which are of enzyme bio-receptors and aptam-
ers. h erefore, a biosensor with an intrinsic electrochemical transduction
method and DNA as a bio-receptor is called DNA biosensor which is based
on bio-receptor or ai nity biosensor likely to be based on bio-recognition
principle or electrochemical DNA biosensor such as both the bio-recep-
tor and transducer are the name used in this writing form of literature.
Other biosensors can be named generally as immune-sensor or antibody
