Hydrogel holographic sensors for detection of components in biological fluids

Holographic sensors based on the hydrogels containing affinity groups sensitive to certain components of gaseous and liquid mixtures represent a promising class of sensors. These sensors have some advantages: the simple qualitative visual way of the information readout, exploitation simplicity, reversibility, wide spectrum of application, and a low cost of manufacturing. The semi quantitative and quantitative readout requires a corresponding design of the reading device. Sensor represents a thick hologram constructed in a hydrogel film containing the silver halogen nanocrystals. The sensor reflects the light of the same wavelength which was used for the hologram construction. After the contact with an analyte, the analyte sensitive matrix changed its configuration, and the distances between the silver layers in the hologram were also changed. As a result, the wavelength of the reflected light also changes.