Abstract: The present invention relates to sensors for detecting the presence or measuring the concentration of a target analyte, the sensor comprising: (i) a first phase comprising a first crosslinked polymer; (ii) a second phase comprising a second crosslinked polymer; and (ill) a target analyte recognition agent; the first phase and second phase arranged to form an optical grating. The first crosslinked polymer comprises low amounts of a crosslinking agent. The present invention also relates to methods of making a sensor for detecting the presence or measuring the concentration of a target analyte.

Abstract: A method for the production of a holographic sensor which comprises a support medium supporting a reflection hologram wherein the support medium interacts with its physical or chemical environment to create an optical response which is a change in one or more optical properties of the hologram, the method comprising the steps of: a) introducing a colloidal dispersion of a recording material into the support medium; and b) ablating the colloidal particles of the recording material using a pulsed laser to form the holographic element in the support medium. The method of production can be used to introduce a reflection holographic grating into a hydrophobic support medium, in particular, polydimethylsiloxane (PDMS), which possesses an extraordinary ability to swell in the presence of both liquid and/or gaseous low molecular weight hydrocarbons and organic solvents and thus has many applications as a holographic sensor.

Abstract: A method for the production of a holographic sensor which comprises a support medium supporting a reflection hologram wherein the support medium interacts with its physical or chemical environment to create an optical response which is a change in one or more optical properties of the hologram, the method comprising the steps of: a) introducing a colloidal dispersion of a recording material into the support medium; and b) ablating the colloidal particles of the recording material using a pulsed laser to form the holographic element in the support medium. The method of production can be used to introduce a reflection holographic grating into a hydrophobic support medium, in particular, polydimethylsiloxane (PDMS), which possesses an extraordinary ability to swell in the presence of both liquid and/or gaseous low molecular weight hydrocarbons and organic solvents and thus has many applications as a holographic sensor.

Abstract: A sensor comprises respective acceptor and donor compounds immobilised in or on a matrix including a glucose-binding boronate and a cationic species, whereby the spacing between the acceptor and donor compounds is reduced in the presence of glucose. For example a holographic sensor comprises a glucose-binding boronate and a cationic species held within the sensor.

Abstract: An ophthalmic device which comprises a holographic element comprising a medium comprising a phenylboronic acid group and, disposed therein, a hologram, wherein an optical characteristic of the element changes as a result of a variation of a physical property of the medium, and wherein the variation arises as a result of interaction between the medium and an analyte present in an ocular fluid.

Abstract: 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.

Abstract: A sensor for the detection of an analyte comprising a cis-diol moiety, which comprises a holographic element comprising a medium and a hologram disposed throughout the volume of the medium, wherein an optical characteristic of the element changes as a result of a variation of a physical property occurring throughout the volume of the medium, and wherein the medium is a polymer comprising a group of formula (i) wherein n is 0, 1, 2, 3 or 4; each X (if present) is independently is an atom or group which, via an electronic effect, promotes formation of a tetrahedral geometry about the boron atom; and Y is a spacer which, when n is 0 or otherwise optionally, is an atom or group which, via an electronic effect, promotes formation of a tetrahedral geometry about the boron atom. Such a sensor may be used for the detection of glucose.

Abstract: An ophthalmic device which comprises a holographic element comprising a medium comprising a phenylboronic acid group and, disposed therein, a hologram, wherein an optical characteristic of the element changes as a result of a variation of a physical property of the medium, and wherein the variation arises as a result of interaction between the medium and an analyte present in an ocular fluid.

Abstract: A sensor for the detection of an analyte comprising a cis-diol moiety, which comprises a holographic element comprising a medium and a hologram disposed throughout the volume of the medium, wherein an optical characteristic of the element changes as a result of a variation of a physical property occurring throughout the volume of the medium, and wherein the medium is a polymer comprising a group of formula (I): wherein n is 0, 1, 2, 3 or 4; each X (if present) is independently is an atom or group which, via an electronic effect, promotes formation of a tetrahedral geometry about the boron atom; and Y is a spacer which, when n is 0 or otherwise optionally, is an atom or group which, via an electronic effect, promotes formation of a tetrahedral geometry about the boron atom. Such a sensor may be used for the detection of glucose.

Abstract: An ophthalmic device which comprises a holographic element comprising a medium comprising a phenylboronic acid group and, disposed therein, a hologram, wherein an optical characteristic of the element changes as a result of a variation of a physical property of the medium, and wherein the variation arises as a result of interaction between the medium and an analyte present in an ocular fluid.

Abstract: A method for the production of a holographic sensor which comprises a support medium supporting a reflection hologram wherein the support medium interacts with its physical or chemical environment to create an optical response which is a change in one or more optical properties of the hologram, the method comprising the steps of: a) introducing a colloidal dispersion of a recording material into the support medium; and b) ablating the colloidal particles of the recording material using a pulsed laser to form the holographic element in the support medium. The method of production can be used to introduce a reflection holographic grating into a hydrophobic support medium, in particular, polydimethylsiloxane (PDMS), which possesses an extraordinary ability to swell in the presence of both liquid and/or gaseous low molecular weight hydrocarbons and organic solvents and thus has many applications as a holographic sensor.

Abstract: A sensing method, which comprises subjecting a holographic sensor to an external physical interaction to which the sensor is sensitive, and observing a change in the holographic image.

Abstract: A sensor comprises respective acceptor and donor compounds immobilised in or on a matrix including a glucose-binding boronate and a cationic species, whereby the spacing between the acceptor and donor compounds is reduced in the presence of glucose. For example a holographic sensor comprises a glucose-binding boronate and a cationic species held within the sensor.

Abstract: 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.

Abstract: An ophthalmic device which comprises a holographic element comprising a medium comprising a phenylboronic acid group and, disposed therein, a hologram, wherein an optical characteristic of the element changes as a result of a variation of a physical property of the medium, and wherein the variation arises as a result of interaction between the medium and an analyte present in an ocular fluid.

Abstract: An array of discrete sensors disposed on a substrate, each sensor comprising a holographic support medium and a hologram disposed throughout the volume of the medium, whereby interaction with an analyte results in a variation of a property of the medium.

Abstract: A method for the detection of an analyte in a fluid, comprising contacting the fluid with a holographic element comprising a medium and a hologram disposed throughout the volume of the medium, wherein an optical characteristic of the element changes as a result of a variation of a physical property occurring throughout the volume of the medium, wherein the variation arises as a result of interaction between the medium and the analyte, and wherein the reaction and the variation are reversible; and detecting any change of the optical characteristic.

Abstract: A sensing method, which comprises subjecting a holographic sensor to an external physical interaction to which the sensor is sensitive, and observing a change in the holographic image.

Abstract: A sensor (8) comprises 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 of the medium, and wherein the hologram is formed as a non-planar mirror.

Abstract: A sensor comprising a medium and, disposed throughout the volume thereof, a holographic element whose fringes are defined by different degrees of swellability in a liquid.