Biosensors is a new class of analytical devices using immobilized biological materials to recognise molecules. Optical biosensors have high sensitivity and resolution for detection and quantitative analysis of chemical and biological processes. Action of these sensors is based on optical effects such as light absorption, reflection of the primary light flux, luminescence, surface plasmon resonance and the effect of photonic band gaps. As the signal from the optical biosensor can serve changes of wavelength, intensity, phase and polarization of the light, wich depends from the concentration of the analyte and environment acts on them.
Now a days Photonic crystal fiber (PCF) is one of the most prospective sensitive elements of fiber-optic sensors of physical and chemical values, the use of which should significantly enhance the ability of traditional fiber biosensors.