Abstract: A sensor including a sensing layer is disposed over an electrode or an optode and a layer-by-layer assembled mass transport limiting membrane disposed over the sensing layer. The membrane includes at least one layer of a polyanionic or polycationic material. The assembled layers of the membrane are typically disposed in an alternating manner. The sensor also optionally includes a biocompatible membrane.

Abstract: A continuous glucose monitoring system including a sensor configured to detect one or more glucose levels, a transmitter operatively coupled to the sensor, the transmitter configured to receive the detected one or more glucose levels, the transmitter further configured to transmit signals corresponding to the detected one or more glucose levels, and a receiver operatively coupled to the transmitter configured to receive transmitted signals corresponding to the detected one or more glucose levels, and methods thereof, are disclosed. In one aspect, the transmitter may be configured to transmit a current data point and at least one previous data point, the current data point and the at least one previous data point corresponding to the detected one or more glucose levels.

Abstract: A small volume sensor, and methods of making, for determining the concentration of an analyte, such as glucose or lactate, in a biological fluid, such as blood or serum, using techniques such as coulometry, amperometry, and potentiometry. The sensor includes a working electrode and a counter electrode, and can include an insertion monitoring trace to determine correct positioning of the sensor in a connector. In one embodiment, the sensor determines the concentration of the analyte by discharging an amount of charge into the sample, determining the time needed to discharge the charge, and determining the current used to electrolyze a portion of the analyte using the amount of charge and the amount of time.

Abstract: A lancing device and method for self-collecting a sample of body fluid by penetrating a body tissue at a sampling site. The invention includes a housing geometry configured for ease of use at different sampling sites on the body, even by persons having reduced dexterity and/or poor vision. Depth of penetration is selectively controlled by adjusting the stroke range of a spring-driven lancet carrier. A pressure applicator is included for stimulating flow of the body fluid. A transparent portion permits observation of the sampling site.

Abstract: An in vivo electrochemical sensor including a working electrode, and an analyte-responsive sensing layer proximate the working electrode. The sensing layer is exposed at an edge of the sensor, wherein the sensor signal is limited, at least in part, by mass transport of analyte to the sensing layer. The sensor is configured and arranged for implantation into the body of a mammal for contact with body fluids of the mammal. The analyte diffuses to the sensing element via the edge of the sensor, thereby restricting mass transport of the analyte to the sensing element. This is because the solution-contacting surface area of the sensor edge is much smaller than an open face of the sensing layer.

Abstract: A sensor including a sensing layer is disposed over an electrode or an optode and a layer-by-layer assembled mass transport limiting membrane disposed over the sensing layer. The membrane includes at least one layer of a polyanionic or polycationic material. The assembled layers of the membrane are typically disposed in an alternating manner. The sensor also optionally includes a biocompatible membrane.

Abstract: An analyte monitor includes a sensor, a sensor control unit, and a display unit. The sensor has, for example, a substrate, a recessed channel formed in the substrate, and conductive material disposed in the recessed channel to form a working electrode. The sensor control unit typically has a housing adapted for placement on skin and is adapted to receive a portion of an electrochemical sensor. The sensor control unit also includes two or more conductive contacts disposed on the housing and configured for coupling to two or more contact pads on the sensor. A transmitter is disposed in the housing and coupled to the plurality of conductive contacts for transmitting data obtained using the sensor. The display unit has a receiver for receiving data transmitted by the transmitter of the sensor control unit and a display coupled to the receiver for displaying an indication of a level of an analyte.

Abstract: A sensor utilizing a non-leachable or diffusible redox mediator is described. The sensor includes a sample chamber to hold a sample in electrolytic contact with a working electrode, and in at least some instances, the sensor also contains a non-leachable or a diffusible second electron transfer agent. The sensor and/or the methods used produce a sensor signal in response to the analyte that can be distinguished from a background signal caused by the mediator. The invention can be used to determine the concentration of a biomolecule, such as glucose or lactate, in a biological fluid, such as blood or serum, using techniques such as coulometry, amperometry, and potentiometry. An enzyme capable of catalyzing the electrooxidation or electroreduction of the biomolecule is typically provided as a second electron transfer agent.

Abstract: A sensor utilizing a non-leachable or diffusible redox mediator is described. The sensor includes a sample chamber to hold a sample in electrolytic contact with a working electrode, and in at least some instances, the sensor also contains a non-leachable or a diffusible second electron transfer agent. The sensor and/or the methods used produce a sensor signal in response to the analyte that can be distinguished from a background signal caused by the mediator. The invention can be used to determine the concentration of a biomolecule, such as glucose or lactate, in a biological fluid, such as blood or serum, using techniques such as coulometry, amperometry, and potentiometry. An enzyme capable of catalyzing the electrooxidation or electroreduction of the biomolecule is typically provided as a second electron transfer agent.

Abstract: Novel transition metal complexes of iron, cobalt, ruthenium, osmium, and vanadium are described. The transition metal complexes can be used as redox mediators in enzyme based electrochemical sensors. In such instances, transition metal complexes accept electrons from, or transfer electrons to, enzymes at a high rate and also exchange electrons rapidly with the sensor. The transition metal complexes include at least one substituted or unsubstituted biimidazole ligand and may further include a second substituted or unsubstituted biimidazole ligand or a substituted or unsubstituted bipyridine or pyridylimidazole ligand. Transition metal complexes attached to polymeric backbones are also described.

Abstract: A sensor for the detection and measurement of an analyte in a biofluid. The sensor includes two enzymes. One type of sensor measures the concentration of hydrogen peroxide using a thermostable peroxidase enzyme that is immobilized in a redox hydrogel to form a sensing layer on a working electrode. This sensor also includes a hydrogen peroxide-generating second enzyme which is insulated from the redox hydrogel and electrode. This second enzyme generates hydrogen peroxide in response to the presence of an analyte or analyte-generated compound. The second enzyme may be insulated from the electrode by placement of an electrically insulating layer between the sensing layer and the second enzyme layer. Alternatively, the second enzyme is immobilized in an inorganic polymeric matrix, preferably made using a sol-gel polymerization process. Such matrices include those made of silica. Often, the second enzyme is stabilized by immobilization in a sol-gel.

Abstract: Novel transition metal complexes of iron, cobalt, ruthenium, osmium, and vanadium are described. The transition metal complexes can be used as redox mediators in enzyme-based electrochemical sensors. The transition metal complexes include substituted or unsubstituted(pyridyl)imidazole ligands. Transition metal complexes attached to polymeric backbones are also described.

Abstract: An in vivo electrochemical sensor including a working electrode, and an analyte-responsive sensing layer proximate the working electrode. The sensing layer is exposed at an edge of the sensor, wherein the sensor signal is limited, at least in part, by mass transport of analyte to the sensing layer. The sensor is configured and arranged for implantation into the body of a mammal for contact with body fluids of the mammal. The analyte diffuses to the sensing element via the edge of the sensor, thereby restricting mass transport of the analyte to the sensing element. This is because the solution-contacting surface area of the sensor edge is much smaller than an open face of the sensing layer.

Abstract: A sensor designed to determine the amount and concentration of analyte in a sample having a volume of less than about 1 &mgr;L. The sensor has a working electrode coated with a non-leachable redox mediator. The redox mediator acts as an electron transfer agent between the analyte and the electrode. In addition, a second electron transfer agent, such as an enzyme, can be added to facilitate the electrooxidation or electroreduction of the analyte. The redox mediator is typically a redox compound bound to a polymer. The preferred redox mediators are air-oxidizable.

Abstract: Rapid electrochemical verification of the amplification of DNA by a polymerase chain reaction in a small sample of the PCR product.

Abstract: A region of skin, other than the fingertips, is stimulated. After stimulation, an opening is created in the skin (e.g., by lancing the skin) to cause a flow of body fluid from the region. At least a portion of this body fluid is transported to a testing device where the concentration of analyte (e.g., glucose) in the body fluid is then determined. It is found that the stimulation of the skin provides results that are generally closer to the results of measurements from the fingertips, the traditional site for obtaining body fluid for analyte testing.

Abstract: A process for the manufacture of small sensors with reproducible surfaces, including electrochemical sensors. One process includes forming channels in the surface of a substrate and disposing a conductive material in the channels to form an electrode. The conductive material can also be formed on the substrate by other impact and non-impact methods. In a preferred embodiment, the method includes the steps of providing a continuous substrate web, and disposing a pattern of a conductive material on the continuous substrate web to form one or more working electrodes and/or counter electrodes.

Abstract: An analyte monitor includes a sensor, a sensor control unit, and a display unit. The sensor has, for example, a substrate, a recessed channel formed in the substrate, and conductive material disposed in the recessed channel to form a working electrode. The sensor control unit typically has a housing adapted for placement on skin and is adapted to receive a portion of an electrochemical sensor. The sensor control unit also includes two or more conductive contacts disposed on the housing and configured for coupling to two or more contact pads on the sensor. A transmitter is disposed in the housing and coupled to the plurality of conductive contacts for transmitting data obtained using the sensor. The display unit has a receiver for receiving data transmitted by the transmitter of the sensor control unit and a display coupled to the receiver for displaying an indication of a level of an analyte.

Abstract: A reusable ceramic skin-piercing device. The skin-piercing device is capable of piercing the skin so as to make a sample of biological fluid available for an assay. In one embodiment, the skin-piercing device includes a skin-piercing element which is heated prior to use to a sufficiently high temperature to kill or deactivate pathogenic microorganisms. The device is heat-sterilized, being heated by passing an electrical current through a resistive element in thermal contact with the heat-conducting ceramic piercer. In another embodiment, the skin-piercing device includes a sleeve of elastomeric material with a sterilizing agent disposed in contact with the skin-piercing element. The sterilizing agent sterilizes the skin-piercing element after use. The skin-piercing element is made of a hard refractory ceramic material. The ceramic material is optionally a composite, for example, a composite of a ceramic material and a metal, or multiple ceramic materials.

Abstract: A measurement module for glucose testing includes a glucose testing measurement module housing, a test strip receptacle formed in the housing, and a connector portion formed in the housing and shaped to permit mechanical removable attachment of the housing to a hand-held computer. Electronics determine the amount of glucose present in a sample of body fluid, when the test strip is positioned in the receptacle and the body fluid is placed on a test strip, and communicate the glucose amount to the hand-held computer via the connector portion.