Aspects of recent development of immunosensors - Electrochemical Sensors, Biosensors and Their Biomedical Applications - page 248

scale and widely applied in clinical diagnosis. Moreover, there have been increasing
reports focusing on the development of microfl uidic immunosensor systems for pro-
teomics and drug discovery in recent years [178]. Microfl uidic system integrating mul-
tiple processes in a single device generally seeks to improve analytical performance by
reducing the reagent consumption and the analysis time, and increasing reliability and
sensitivity through automation. The micro total analysis systems ( TAS) are already

under development and should represent the future of high throughput immuno-tests
[179]. In addition, with the development of protein engineering technology and molec-
ular biology techniques, more fl exible antibodies suitable for immunosensing applica-
tions may be expected. For example, the recombinant or fusion approach is powerful
in the production of antibodies and antibody derivates. Use of various new generations
of antibodies should lead to the enhancement of activity and stability of the immo-
bilized bio-species and even the improvement of the regeneration and sensitivity of
the immunosensors. As an inspiringly illustrative instance, aptamers are beginning to
emerge as a class of synthetic oligonucleotides or molecules that rival antibodies in
both therapeutic and diagnostic applications [180-182]. Baldrich and coworkers fi rst
demonstrated the exploitation of an aptamer in an extremely rapid and highly sensitive
displacement assay, the displacement enzyme-linked aptamer assay, using enzyme-
labeled target as a suboptimal displaceable molecule [182].
To sum up, immunosensors are now becoming one of the most widely used analyti-
cal techniques, embracing a vast repertoire of analytes that are detected by a diverse
range of transducer devices. The enormous potential of immunosensors in clinical
diagnosis, environmental analysis, and biological process monitoring has been widely
accepted and increasing efforts have been devoted to these fi elds. In particular, with the
continual development of transducer technology, laser technology, nano-sized material
technology, and antibody engineering technology, immunosensors based on the appli-
cation of these technologies should be inevitably powerful tools in increasingly wide
analytical areas [9].

µ

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