Abstract: Devices and methods are provided for determining the concentration of a reduced form of a redox species. For example, a device can include a working electrode and a counter electrode spaced by a predetermined distance so that reaction produces from the counter electrode arrive at the working electrode. An electric potential difference can be applied between the electrodes, and the potential of the working electrode can be selected such that the rate of electro-oxidation of the reduced form of the species is diffusion controlled. Current as a function of time can be determined, the magnitude of the steady state current can be estimated, and a value indicative of the diffusion coefficient and/or of the concentration of the reduced form of the species can be obtained from the change in current with time and the magnitude of the steady state current. Other embodiments of apparatuses, devices, and methods are also provided.

Abstract: Devices and methods are provided for determining the concentration of a reduced form of a redox species. For example, a device can include a working electrode and a counter electrode spaced by a predetermined distance so that reaction produces from the counter electrode arrive at the working electrode. An electric potential difference can be applied between the electrodes, and the potential of the working electrode can be selected such that the rate of electro-oxidation of the reduced form of the species is diffusion controlled. Current as a function of time can be determined, the magnitude of the steady state current can be estimated, and a value indicative of the diffusion coefficient and/or of the concentration of the reduced form of the species can be obtained from the change in current with time and the magnitude of the steady state current. Other embodiments of apparatuses, devices, and methods are also provided.

Abstract: Devices and methods are provided for determining the concentration of a reduced form of a redox species. For example, a device can include a working electrode and a counter electrode spaced by a predetermined distance so that reaction produces from the counter electrode arrive at the working electrode. An electric potential difference can be applied between the electrodes, and the potential of the working electrode can be selected such that the rate of electro-oxidation of the reduced form of the species is diffusion controlled. Current as a function of time can be determined, the magnitude of the steady state current can be estimated, and a value indicative of the diffusion coefficient and/or of the concentration of the reduced form of the species can be obtained from the change in current with time and the magnitude of the steady state current. Other embodiments of apparatuses, devices, and methods are also provided.

Abstract: Devices and methods are provided for determining the concentration of a reduced form of a redox species. For example, a device can include a working electrode and a counter electrode spaced by a predetermined distance so that reaction produces from the counter electrode arrive at the working electrode. An electric potential difference can be applied between the electrodes, and the potential of the working electrode can be selected such that the rate of electro-oxidation of the reduced form of the species is diffusion controlled. Current as a function of time can be determined, the magnitude of the steady state current can be estimated, and a value indicative of the diffusion coefficient and/or of the concentration of the reduced form of the species can be obtained from the change in current with time and the magnitude of the steady state current. Other embodiments of apparatuses, devices, and methods are also provided.

Abstract: A hollow electrochemical cell is provided. In one exemplary embodiment, a hollow electrochemical cell includes two sets of electrodes and an opening for admitting an analyte to the cell. At least one of the two sets of electrodes can be in fluid communication with the opening. Further, a first set of electrodes can include a working electrode spaced from a counter or counter/reference electrode by less than 500 ?m one embodiment the working and counter or counter/reference electrodes are not co-planer. In another embodiment the working and counter or counter/reference electrodes are of substantially corresponding area. In yet another embodiment the working and counter or counter/reference electrodes are spaced from 100 to 200 ?m apart. The first set of electrodes and the second set of electrodes can be spaced apart by greater than about 500 ?m. Other embodiments of a hollow electrochemical cell are also provided, as are several embodiments of a glucose sensor.

Abstract: A method for determining the concentration of a reduced or oxidized form of a redox species is provided. In one exemplary embodiment, an electrochemical apparatus is provided in which the apparatus includes a hollow electrochemical cell for measuring a concentration of glucose in a blood sample, a current of the cell is measured, and a concentration of a redox mediator is determined, at least in part from, a measured current of the cell. The hollow electrochemical cell can include at least one non-metal working electrode, at least one counter electrode or counter/reference electrode, and a spacer interposed between the working electrode and the counter or counter/reference electrode. In one embodiment the working electrode and the counter or counter/reference electrode are not co-planer and are separated by a distance of from about 20 microns to about 200 microns.

Abstract: A method of manufacture of an electrochemical cell is provided. In one exemplary embodiment, at least one non-metal working electrode is provided, at least one counter electrode or counter/reference electrode is provided such that it is not co-planer with respect to the working electrode, and a spacer is provided interposed between the working and counter or counter/referenced electrode. In one embodiment the counter or counter/reference electrode can be separated from the working electrode by a distance of from about 20 microns to about 200 microns. Alternatively, the cell can have an effective volume of less than 1.5 microliters. A method of manufacture of an electrochemical apparatus is also provided. The method can include providing both a hollow electrochemical cell for measuring a concentration of glucose in a blood sample and a mechanism configured to determine a concentration of a redox mediator from, at least in part, a measured current of the cell.

Abstract: A method for determining the concentration of a reduced or oxidized form of a redox species is provided. In one exemplary embodiment, an electrochemical apparatus is provided in which the apparatus includes a hollow electrochemical cell for measuring a concentration of glucose in a blood sample, a current of the cell is measured, and a concentration of a redox mediator is determined, at least in part from, a measured current of the cell. The hollow electrochemical cell can include at least one non-metal working electrode, at least one counter electrode or counter/reference electrode, and a spacer interposed between the working electrode and the counter or counter/reference electrode. In one embodiment the working electrode and the counter or counter/reference electrode are not co-planer and are separated by a distance of from about 20 microns to about 200 microns.

Abstract: A hollow electrochemical cell is provided. In one exemplary embodiment, a hollow electrochemical cell includes two sets of electrodes and an opening for admitting an analyte to the cell. At least one of the two sets of electrodes can be in fluid communication with the opening. Further, a first set of electrodes can include a working electrode spaced from a counter or counter/reference electrode by less than 500 ?m. In one embodiment the working and counter or counter/reference electrodes are not co-planer. In another embodiment the working and counter or counter/reference electrodes are of substantially corresponding area. In yet another embodiment the working and counter or counter/reference electrodes are spaced from 100 to 200 ?m apart. The first set of electrodes and the second set of electrodes can be spaced apart by greater than about 500 ?m. Other embodiments of a hollow electrochemical cell are also provided, as are several embodiments of a glucose sensor.

Abstract: This invention relates to a biosensor and more particularly to an electrochemical biosensor for determining the concentration of an analyte in a carrier. The invention is particularly useful for determining the concentration of glucose in blood and is described herein with reference to that use but it should be understood that the invention is applicable to other analytic determinations.

Abstract: This invention relates to a biosensor and more particularly to an electrochemical biosensor for determining the concentration of an analyte in a carrier. The invention is particularly useful for determining the concentration of glucose in blood and is described herein with reference to that use but it should be understood that the invention is applicable to other analytic determinations.

Abstract: A reactor for preparing carbon nanotubes comprising a reaction chamber, at least one support means located within said reaction chamber capable of supporting a substrate, said substrate being capable of supporting carbon nanotube growth, at least one heating element located within said reaction chamber capable of providing localized heating to said substrate within said reaction chamber, and means for passing a gaseous carbonaceous material into said reaction chamber such that is passes over the contacts said substrate.

Abstract: A reactor for preparing carbon nanotubes comprising a reaction chamber, at least one support means located within said reaction chamber capable of supporting a substrate, said substrate being capable of supporting carbon nanotube growth, at least one heating element located within said reaction chamber capable of providing localized heating to said substrate within said reaction chamber, and means for passing a gaseous carbonaceous material into said reaction chamber such that is passes over the contacts said substrate.

Abstract: A biosensor for use in determining a concentration of a component in an aqueous liquid sample is provided including: an electrochemical cell having a first electrically resistive substrate having a thin layer of electrically conductive material, a second electrically resistive substrate having a thin layer of electrically conductive material, the substrates being disposed with the electrically conductive materials facing each other and being separated by a sheet including an aperture, the wall of which aperture defines a cell wall and a sample introduction aperture whereby the aqueous liquid sample may be introduced into the cell; and a measuring circuit.

Abstract: A biosensor for use in determining a concentration of a component in an aqueous liquid sample is provided including: an electrochemical cell having a first electrically resistive substrate having a thin layer of electrically conductive material, a second electrically resistive substrate having a thin layer of electrically conductive material, the substrates being disposed with the electrically conductive materials facing each other and being separated by a sheet including an aperture, the wall of which aperture defines a cell wall and a sample introduction aperture whereby the aqueous liquid sample may be introduced into the cell; and a measuring circuit.

Abstract: This invention relates to a biosensor and more particularly to an electrochemical biosensor for determining the concentration of an analyte in a carrier. The invention is particularly useful for determining the concentration of glucose in blood and is described herein with reference to that use but it should be understood that the invention is applicable to other analytic determinations.

Abstract: This invention relates to a biosensor and more particularly to an electrochemical biosensor for determining the concentration of an analyte in a carrier. The invention is particularly useful for determining the concentration of glucose in blood and is described herein with reference to that use but it should be understood that the invention is applicable to other analytic determinations.

Abstract: This invention relates to a biosensor and more particularly to an electrochemical biosensor for determining the concentration of an analyte in a carrier. The invention is particularly useful for determining the concentration of glucose in blood and is described herein with reference to that use but it should be understood that the invention is applicable to other analytic determinations.

Abstract: A biosensor for use in determining a concentration of a component in an aqueous liquid sample is provided including: an electrochemical cell having a first electrically resistive substrate having a thin layer of electrically conductive material, a second electrically resistive substrate having a thin layer of electrically conductive material, the substrates being disposed with the electrically conductive materials facing each other and being separated by a sheet including an aperture, the wall of which aperture defines a cell wall and a sample introduction aperture whereby the aqueous liquid sample may be introduced into the cell; and a measuring circuit.

Abstract: This invention relates to a biosensor and more particularly to an electrochemical biosensor for determining the concentration of an analyte in a carrier. The invention is particularly useful for determining the concentration of glucose in blood and is described herein with reference to that use but it should be understood that the invention is applicable to other analytic determinations.