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: 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: The present invention relates to a process for the detection of an analyte in a sample, comprising a) bringing the sample into contact with a first ligand which binds specifically to the analyte and which is immobilized on a substrate, and b) prior to or subsequent to step (a), bringing the sample into contact with a second ligand which binds specifically to the analyte and which includes a label: wherein the substrate comprises a holographic sensor comprising a support medium having a hologram disposed therein or thereon and the label causes an optical property of the sensor to change by interaction of the sensor with the label or, following the additional step of contacting the substrate with a reagent, by interaction of the sensor with a species produced by reaction of the label with the reagent, thereby indicating the presence of bound analyte.

Abstract: A method of making a holographic device (4) comprises the steps of: forming a heterogeneous support medium (2) having at least two regions (1) which are heterogeneous; placing the heterogeneous support medium under recording conditions, e.g. in a liquid X, which are selected to change one or more physical properties of the heterogeneous support medium, wherein the extent or nature of the change in the physical property or physical properties is different in at least two of the heterogeneous regions; recording a holographic image in the heterogeneous support medium while it is under recording conditions; and removing the heterogeneous support medium from recording conditions. Such a device can be used for security and authentication.

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 method of measuring the amount of an analyte in a sample, comprises (a) passing the sample through a flow channel in or on a holographic sensor, wherein the analyte interacts with and is retained by the sensor and wherein the interaction of the analyte changes an optical property of the sensor, and (b) monitoring analyte interaction, wherein the distance along the flow channel at which analyte interaction occurs or the area of the channel over which analyte interaction occurs, indicates the amount of analyte in the sample. Further, a method of detecting an analyte in a sample, comprises (a) passing the sample through a flow channel in or on a holographic sensor, wherein the analyte interacts with the sensor, thereby changing an optical property of the sensor, and wherein the flow channel defines a symbol; and (b) detecting the analyte by observing the appearance, disappearance or change in appearance of the symbol.

Abstract: The present invention relates to a process for the detection of an analyte in a sample, comprising a) bringing the sample into contact with a first ligand which binds specifically to the analyte and which is immobilised on a substrate, and b) prior to or subsequent to step (a), bringing the sample into contact with a second ligand which binds specifically to the analyte and which includes a label: wherein the substrate comprises a holographic sensor comprising a support medium having a hologram disposed therein or thereon and the label causes an optical property of the sensor to change by interaction of the sensor with the label or, following the additional step of contacting the substrate with a reagent, by interaction of the sensor with a species produced by reaction of the label with the reagent, thereby indicating the presence of bound analyte.

Abstract: In a method of determining the effectiveness of a sterilization procedure using a biological indicator, the biological indicator comprises a holographic sensor and spores or an enzyme. The method and the biological indicator rely on the holographic sensor to indicate the effectiveness of me sterilisation procedure and do not require a conventional pH indicator, a fluorophore or chromophore.

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 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.