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: The invention relates to a sensor comprising a medium and, disposed therein, a hologram, wherein an optical characteristic of the medium changes as a result of a variation in a physical property of the medium, wherein the fringes of the hologram are formed by silver grains and wherein the medium comprises a material which does not bind silver. The brightness and sensitivity of such holographic sensors is increased as a result of reduction in the levels of unwanted (“background”) silver binding.

Abstract: A method of making a product containing a hologram which has at least two replay colours when viewed at a given angle, the method comprising the steps of: (i) recording holographic elements at each of at least two different angles in a master; and (ii) copying the master. The principle of the system is demonstrated by creating 2 surface relief objects, A and B on top of a mirror background. When a holographic recording medium is placed on top of this surface relief object and then illuminated with a coherent laser beam, interference patterns are recorded and developed within the polymer which describe the relief patterns (C-E). When the hologram is illuminated with white light and viewed normal to the hologram surface, the separation between the fringes relative to the viewing angle then becomes da and dc for surface relief objects A and B respectively (Figures C and E) and remains the same for the mirror (Figure D).

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: A sensing method comprises irradiating a sensor having a medium including a light-sensitive holographic element, and observing a change in the holographic image.

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: The invention relates to a sensor comprising a medium and, disposed therein, a hologram, wherein an optical characteristic of the medium changes as a result of a variation in a physical property of the medium, wherein the fringes of the hologram are formed by silver grains and wherein the medium comprises a material which does not bind silver. The brightness and sensitivity of such holographic sensors is increased as a result of reduction in the levels of unwanted (“background”) silver binding.

Abstract: A method of recording a master hologram comprises projecting a beam of coherent light, e.g. using a laser (1) through, in turn, a holographic recording medium (8) and a transparent object (22), into a diffuse reflective surface (23), wherein the object is non-holographic and wherein the medium, the object and the surface are in substantially linear arrangement such that light reflected by the surface interferes in the medium with light projected therethrough.

Abstract: A method for the detection of an analyte in a fluid, which comprises 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, and wherein the variation arises as a result of interaction between the medium and the analyte; and detecting any change of the optical characteristic of the element; wherein (a) the medium comprises a group which is capable of reacting with the analyte, wherein the analyte or the group is capable of existing in a plurality of forms, and the detecting is conducted in the presence of a first catalyst which is capable of catalysing the conversion of a relatively less reactive form of the analyte or group to a relatively more reactive form; or (b) the fluid comprises a component, other than the analyte, which is capable of interacting with the medium, and the detecti

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 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 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.