Immunosensors are devices that comprise both a biomolecular recognition system, such as an
antibody and its corresponding antigen, and a transducer to translate the high affinity and specific
binding event into a physical signal.
Antibodies are produced by an immunological response to the presence of a foreign substance called an
antigen. Antibodies may be immobilised onto a variety of platforms including bulk planar surfaces and
nanoparticles by either covalent or adsorption strategies. Different interfaces between the biocomponents
and the detector are available to monitor in ‘real-time’ the signal generated by biological
interactions. The transducers detect, for example, the change in electron transfer, absorbance,
fluorescence, refractive index, mass change or heat transfer as the antibody binds to the antigen of
interest. Such analytical devices have allowed a wide range of analytes to be identified and quantified
such as pathogens, toxins, environmental food contaminants and disease biomarkers.
The demand for sensitive, rapid, and ‘on-site’ techniques has taken advantage of the latest advances in
microfluidics and nanotechnology. This chapter will highlight current trends in immobilisation,
micro/nano-fluidics/and transducers utilised. A number of examples outlining the exploitation of these
elements in immunosensors and their successful applications will be described.
Keywords: Antibodies, Immunosensors.
