Abstract: A calibrator, for calibrating a sensor, has a calibration chamber for containing a calibration liquid. The liquid comprises water or an aqueous solution of an analyte to be sensed. A hydrogen peroxide-quenching material is provided exposed to the interior of the calibration chamber. The hydrogen peroxide-quenching material contacts the calibration liquid. After the calibration chamber containing the calibration liquid is sterilized by irradiation with gamma radiation, the hydrogen peroxide-quenching material decomposes any hydrogen peroxide formed in the calibration liquid to avoid adverse effects on a sensor placed in contact with the calibration liquid.

Abstract: A calibrator, for calibrating a sensor, has a calibration chamber for containing a calibration liquid. The liquid comprises water or an aqueous solution of an analyte to be sensed. A hydrogen peroxide-quenching material is provided exposed to the interior of the calibration chamber. The hydrogen peroxide-quenching material contacts the calibration liquid. After the calibration chamber containing the calibration liquid is sterilized by irradiation with gamma radiation, the hydrogen peroxide-quenching material decomposes any hydrogen peroxide formed in the calibration liquid to avoid adverse effects on a sensor placed in contact with the calibration liquid.

Abstract: A sensor for detecting and/or quantifying the amount of analyte in a sample, the sensor including: a sensing region; and a barrier layer including a reactive oxygen species (ROS)-quenching, analyte-permeable membrane having an ROS-quenching agent adsorbed to the membrane; wherein the sensor is adapted so that the sample enters the sensing region of the sensor through the barrier layer.

Abstract: A sensor for detecting and/or quantifying the amount of analyte in a sample, the sensor including: a sensing region; and a barrier layer including a reactive oxygen species (ROS)-quenching, analyte-permeable membrane having an ROS-quenching agent adsorbed to the membrane; wherein the sensor is adapted so that the sample enters the sensing region of the sensor through the barrier layer.

Abstract: A method of calibrating a glucose sensor, which method comprises: (a) preparing a first glucose-containing calibration solution by combining water or an aqueous solution with alpha and beta glucose, the alpha and beta glucose being provided in solid form; (b) exposing a glucose sensor to said first glucose-containing calibration solution and determining the sensor output; (c) exposing the glucose sensor to one or more further calibration solutions having different glucose concentrations from each other and from said first glucose-containing calibration solution and determining the sensor output for the or each calibration solution; and (d) determining a calibration curve from the sensor output data collected in steps (b) and (c).

Abstract: A method of quantifying the amount of glucose in a sample is provided herein that may further comprise an interferent such as mannitol. At least two measurements are obtained using measurement methods that differ in their sensitivity to the amount of interferent in the sample, thus enabling the results to be compared to determine whether any interferent is present in the sample.

Abstract: A method of calibrating a reversible-binding sensor for detecting an analyte includes: (i) varying the temperature of a first calibration solution from a first temperature (T1) to a second temperature (T2) while the first calibration solution is in contact with a sensing region of the sensor; (ii) determining the sensor output for the first calibration solution as a function of temperature; (iii) varying the temperature of a second calibration solution from a third temperature (T3) to a fourth temperature (T4) while the second calibration solution is in contact with the sensing region, the second calibration solution having a concentration of analyte which is different from that of the first calibration solution; (iv) determining the sensor output for the second calibration solution as a function of temperature; and (v) using the determined sensor output from steps (ii) and (iv) to calibrate the sensor.

Abstract: A calibrator, for calibrating a sensor, has a calibration chamber for containing a calibration liquid. The liquid comprises water or an aqueous solution of an analyte to be sensed. A hydrogen peroxide-quenching material is provided exposed to the interior of the calibration chamber. The hydrogen peroxide-quenching material contacts the calibration liquid. After the calibration chamber containing the calibration liquid is sterilized by irradiation with gamma radiation, the hydrogen peroxide-quenching material decomposes any hydrogen peroxide formed in the calibration liquid to avoid adverse effects on a sensor placed in contact with the calibration liquid.

Abstract: A sensor for fluorescence measurement comprising: a light source arranged for emitting light to a sample region, wherein the light source intensity is modulatable; an indicator system located at the sample region, said indicator system comprising: a receptor for an analyte; and a fluorophore associated with said receptor, wherein the fluorophore has a fluorescence lifetime that changes in response to the presence of analyte at the receptor; a single photon avalanche diode arranged to receive fluorescence light emitted from said sample region in response to the light incident on the sample region from the light source, and to generate an output signal; a driver arranged to modulate the light source intensity at a first frequency; a bias voltage source arranged to apply a bias voltage to the single photon avalanche diode, wherein the bias voltage is modulated at a second frequency, different from the first frequency, and wherein the bias voltage is above the breakdown voltage of the single photon avalanche diod

Abstract: A glucose sensor for intravascular measurement of glucose concentration wherein the sensor is arranged to measure glucose concentration by monitoring the lifetime of the fluorophore, the sensor comprising:—an indicator system comprising a receptor for selectively binding to glucose and a fluorophore associated with said receptor, wherein the fluorophore has a life-time of less than 100 ns;—a light source;—an optical fibre arranged to direct light from the light source onto the indicator system; —a detector arranged to receive fluorescent light emitted from the indicator system; and—a signal processor arranged to determine information related to a fluorescence lifetime of the fluorophore based on at least the output signal of the detector.

Abstract: A glucose sensor for measurement of glucose in subcutaneous tissue, the sensor comprising: a probe for subcutaneous insertion, the probe containing an indicator system comprising a receptor for selectively binding to glucose and a fluorophore associated with said receptor, wherein the fluorophore has a fluorescence lifetime of less than 100 ns; a detector head which is optically connected to the probe and which is for location outside the body; a light source; and a detector arranged to receive fluorescent light emitted from the indicator system, wherein the light source and detector are optionally located within the detector head; wherein the sensor is arranged to measure glucose concentration in subcutaneous tissue by monitoring the fluorescence lifetime of the fluorophore.

Abstract: The invention provides an optical sensor, e.g a fibre optic sensor, for determining the presence or amount of an analyte in a medium, the sensor having an indicator provided in the form of a fluid. In one aspect, the sensor contains either a solution of the indicator itself, or a solution of a support material which is bonded to the indicator. Dendrimers are examples of suitable support materials.

Abstract: An optical glucose sensor comprising: a sensing region comprising a boronic acid receptor for binding to glucose and a fluorophore associated with said receptor; an optical waveguide for directing incident light onto the sensing region; and a hydrophilic, polymeric, glucose-permeable barrier layer which is provided on at least a part of the sensing region; wherein the sensor is adapted so that glucose enters the sensing region of the sensor through said barrier layer.

Abstract: A method of calibrating a glucose sensor, which method comprises: (a) preparing a first glucose-containing calibration solution by combining water or an aqueous solution with alpha and beta glucose, the alpha and beta glucose being provided in solid form; (b) exposing a glucose sensor to said first glucose-containing calibration solution and determining the sensor output; (c) exposing the glucose sensor to one or more further calibration solutions having different glucose concentrations from each other and from said first glucose-containing calibration solution and determining the sensor output for the or each calibration solution; and (d) determining a calibration curve from the sensor output data collected in steps (b) and (c).

Abstract: A fibre optic sensor for detecting or measuring the concentration of an analyte in a medium, the sensor having a sensing region (1) for insertion into the medium during use, which sensing region comprises a cell containing an indicator for the analyte, wherein the cell comprises a central portion (CE) arranged longitudinally within the fibre and one or more crossing portions (CR1, CR2, CR3) which intersect the central portion.

Abstract: A process is provided for the covalent attachment of an indicator to a plastic optical fibre by functionalising the surface of the optical fibre to provide a polymerisable group, and polymerising an indicator monomer, optionally together with a hydrogel-forming monomer, to the fibre surface. This provides an optical fibre having covalently linked to its surface an indicator, typically an indicator encased in a hydrogel. The plastic optical fibre is useful as a sensor.