The use of a nucleic acids sequence for a specific diagnostics
application was developed in the early 1953 and is still growing
widely (Liu et al., 2012a). The highly specific affinity binding's
reaction between two single strand DNA (ssDNA) chains to
form double stranded DNA (dsDNA) is utilized in the nucleic
acids based biosensor which appoints the nucleic acids as the
biological recognition element. This method has promoted the
development of DNA based sensor from the traditional
method such as coupling of electrophoretic separations and radio iso-tropic which are high cost, hazardous, time consuming
etc. (Parkinson and Pejcic, 2005). This biosensor working
principal is based on recognition of the complementary strand
of ssDNA to form a stable hydrogen bond between two nucleic
acids to become dsDNA. In order to achieve this, an
immobilized ssDNA is used as a probe in a bioreceptor in
which the base sequence is complementary to the target of
interest. Exposure of the target to the probe which results in
hybridization of complementary ssDNA to form dsDNA will
result in the production of a biochemical reaction that allows
the transducer to amplify the signal into an electrical one.
Subsequently, literature shows that the presence of some
linker such as thiol or biotin is needed in the effort to
immobilize the ssDNA onto the sensing surface.