Holographic sensor based on a volume hologram in a porous medium
A sensor for the detection of an analyte, comprising a holographic element comprising a medium and a hologram disposed throughout the volume of the medium, wherein an optical characteristic of the hologram changes as a result of a variation of a physical property occurring throughout the volume of the medium, wherein the medium is obtainable by formation in situ in the presence of a pore-forming agent, wherein the agent is not present in the sensor or does not react with the analyte and the sensor.
1 . A sensor for the detection of an analyte, which comprises a holographic element comprising a medium and a hologram disposed throughout the volume of the medium, wherein an optical characteristic of the hologram changes as a result of a variation of a physical property occurring throughout the volume of the medium, wherein the medium is obtainable by formation in situ in the presence of a pore-forming agent, wherein the agent is not present in the sensor or does not react with the analyte and the sensor.
2 . The sensor according to claim 1 , wherein the physical property is the size of the medium.
3 . The sensor according to claim 1 , wherein the optical characteristic is the reflectance, refractance or absorbance of the holographic element.
4 . The sensor according to claim 1 , wherein the agent is a gas.
5 . The sensor according to claim 1 , wherein the agent is a liquid.
6 . The sensor according to claim 1 , wherein the agent is water.
7 . The sensor according to claim 1 , wherein the agent is a solid obtainable by extraction of the agent after the formation.
8 . The sensor according to claim 1 , wherein the medium is a polymer obtainable by the polymerization of monomers in situ.
9 . The sensor according to claim 8 , wherein the monomers include hydroxyethyl methacrylate.