4 Fabrication of impedimetric biosensors

The fundamental principle behind biosensing is the conversion of a specific biorecognition event into a measurable signal. As described in Section 2.4, a wide variety of bioreceptors can be employed to detect a diverse range of analytes. The signal may be transduced in a variety of ways; electrochemically, optically or mechanically. In the case of impedimetric sensors, a high-affinity interaction between the analyte and bioreceptors, which are often antibodies, gives rise to alterations in the electrical properties of the sensor surface. Therefore, the layer-by-layer construction and the nanostructure of the biosensor surface must be finely-tuned in order to achieve specific, measurable and robust analyte detection within complex patient samples.