US20030080001A1 - Heated electrochemical cell - Google Patents

Heated electrochemical cell Download PDF

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US20030080001A1
US20030080001A1 US10/246,370 US24637002A US2003080001A1 US 20030080001 A1 US20030080001 A1 US 20030080001A1 US 24637002 A US24637002 A US 24637002A US 2003080001 A1 US2003080001 A1 US 2003080001A1
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method according
sample
concentration
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Alastair Hodges
Thomas Beck
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LifeScan Inc
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LifeScan Inc
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Priority to AUPP2388A priority patent/AUPP238898A0/en
Priority to PCT/AU1999/000152 priority patent/WO1999046585A1/en
Priority to US09/659,470 priority patent/US6475360B1/en
Application filed by LifeScan Inc filed Critical LifeScan Inc
Priority to US10/246,370 priority patent/US20030080001A1/en
Assigned to LIFESCAN, INC. reassignment LIFESCAN, INC. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: USF FILTRATION AND SEPARATIONS GROUP INC.
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    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00Investigating or analysing materials by the use of electric, electro-chemical, or magnetic means
    • G01N27/26Investigating or analysing materials by the use of electric, electro-chemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
    • G01N27/28Electrolytic cell components
    • G01N27/30Electrodes, e.g. test electrodes; Half-cells
    • G01N27/327Biochemical electrodes electrical and mechanical details of in vitro measurements
    • G01N27/3271Amperometric enzyme electrodes for analytes in body fluids, e.g. glucose in blood
    • G01N27/3272Test elements therefor, i.e. disposable laminated substrates with electrodes, reagent and channels

Abstract

The invention provides a method for determining the concentration of an analyte in a sample comprising the steps of heating the sample and measuring the concentration of the analyte or the concentration of a species representative thereof in the sample at a predetermined point on a reaction profile by means that are substantially independent of temperature. Also provided is an electrochemical cell comprising a spacer pierced by an aperture which defines a cell wall, a first metal electrode on one side of the spacer extending over one side of the aperture, a second metal electrode on the other side of the spacer extending over the side of the aperture opposite the first electrode, means for admitting a sample to the cell volume defined between the electrodes and the cell wall, and means for heating a sample contained within the cell.

Description

    RELATED APPLICATIONS
  • This application is a division of application Ser. No. 09/659,470, filed Sep. 11, 2000, which is a continuation, under 35 U.S.C. § 120, of copending International Patent Application No. PCT/AU99/00152, filed on Mar. 11, 1999, under the Patent Cooperation Treaty (PCT), which was published by the International Bureau in English on Sep. 16, 1999, which designates the U.S. and claims the benefit of Australian Patent Application No. PP2388, filed on Mar. 12, 1998.[0001]
  • TECHNICAL FIELD
  • This invention relates to a method and apparatus for measuring the concentration of an analyte in solution. [0002]
  • The invention will be described with particular reference to the measurement of the concentration of glucose in blood but is not limited to that use and has general application for the measurement of analytes other than glucose and for solutions other than blood samples. [0003]
  • BACKGROUND ART
  • Persons who suffer from diabetes routinely check their blood glucose concentration and there is a need for simple, reliable and inexpensive means to facilitate such routine testing. [0004]
  • In a common method for conducting the tests, a blood sample is combined with an enzyme for example glucose dehydrogenase (“GDH”); the GDH oxidises glucose and in the process becomes reduced. An oxidising mediator, for example ferricyanide, is allowed to react with the reduced GDH returning the GDH to its initial form and producing ferrocyanide in the process. The concentration of ferrocyanide produced is then sensed for example electrochemically or spectroscopically to produce a signal which can be interpreted to give an estimate of the glucose concentration in the sample. [0005]
  • In our co-pending applications PCT/AU96/00723 and PCT/AU96/00724 (the disclosures of which are incorporated herein by reference) there are described methods and apparatus suitable for electrochemically determining the concentration of glucose in blood by electrochemical measurement. [0006]
  • A preferred method for accurately determining the concentration of an analyte is to react all the analyte present in the sample with reagents that produce a species that can be sensed. This requires that the reaction of the analyte go to completion. [0007]
  • For reaction of GDH with glucose to go to substantial completion typically requires several minutes. This is thought to be due to the time required for the glucose to diffuse out from glucose-containing cells of the blood. As this length of time is unacceptably long for the market, it is more usual to measure the glucose concentration over a shorter period, for example 20-30 seconds and accept a less accurate response or apply a factor to estimate the glucose concentration by kinetic extrapolation for example as outlined in co-pending application PCT/AU96/00723. This expedient shortens the time of the test but can lead to loss of precision of the result. [0008]
  • It is an object of the present invention to provide a method and apparatus which avoids or ameliorates the above-discussed deficiencies in the prior art. [0009]
  • DESCRIPTION OF THE INVENTION
  • According to one aspect the invention consists in a method for determining the concentration of an analyte in a sample comprising the steps of: [0010]
  • heating the sample in a disposable test cell; and [0011]
  • measuring the concentration of the analyte or the concentration of a species representative thereof in the sample at a predetermined point on a reaction profile by means that are substantially independent of the temperature of the sample in the test cell. [0012]
  • Those skilled in the art will understand the term “reaction profile” as used herein to mean the relationship of one reaction variable to another. Often, for example, the reaction profile illustrates the change of concentration of a species with respect to time. Such a profile can provide a skilled addressee with both qualitative and quantitative information, including information as to whether a reaction system has achieved a steady state. [0013]
  • Preferably, the predetermined point on the reaction profile is a steady state, and the species representative of the concentration of the analyte is a mediator, for instance an enzyme mediator. [0014]
  • In one embodiment of the invention the sample is heated by an exothermic reaction produced upon contact of the sample with a suitable reagent or reagents. [0015]
  • In a second embodiment of the invention the sample is heated electrically, for example by means of a current applied to resistive elements associated with the measuring means. [0016]
  • In a highly preferred embodiment the measuring means is an electrochemical cell of the kind described in co-pending applications PCT/AU96/00723 and PCT/AU96/00724 and the sample is heated by application of an alternating voltage signal between electrodes of the sensor. [0017]
  • According to a second aspect the invention consists in an electrochemical cell comprising a spacer pierced by an aperture which defines a cell wall, a first metal electrode on one side of the spacer extending over one side of the aperture, a second metal electrode on the other side of the spacer extending over the side of the aperture opposite the first electrode, means for admitting a sample to the cell volume defined between the electrodes and the cell wall, and means for heating a sample contained within the cell.[0018]
  • BRIEF DESCRIPTION OF THE DRAWINGS
  • The invention will now be more particularly described by way of example only with reference to the accompanying drawings wherein: [0019]
  • FIG. 1 shows schematically a sensor strip according to the invention in a cross-section taken longitudinally through the midline of the sensor strip. [0020]
  • FIG. 2 shows the results of tests conducted in accordance with one embodiment of the present invention for blood samples with varying haematocrits and glucose concentrations. [0021]
  • FIG. 3 shows the results of tests conducted in accordance with another embodiment of the present invention for blood samples with varying haematocritis and glucose concentrations. [0022]
  • FIG. 4 exemplifies the reactions taking place in a cell according to preferred embodiments. [0023]
  • FIG. 5 illustrates the concentration profiles across an electrochemical cell according to the preferred embodiments before the application of an electrical potential, after application of the potential and prior to reaching steady state, and at steady state. [0024]
  • FIG. 6 shows the time dependence of current prior to and after application of electrical potential. [0025]
  • FIG. 7 shows the ferrocyanide concentration profiles across an electrochemical cell according to the preferred embodiments prior to a polarity reversal, after reversal and prior to reaching a steady state, and at steady state. [0026]
  • FIG. 8 shows the time dependence of current prior to and after a polarity reversal. [0027]
  • FIG. 9 shows the time dependence of current prior to and after an interruption of applied potential of 15 seconds. [0028]
  • FIG. 10 shows the reactions in an electrochemical cell with peroxide oxidation. [0029]
  • FIG. 11 shows the time dependence of current when an initial potential sufficient to oxidise hydrogen peroxide is applied. [0030]
  • FIG. 12 describes the cell of FIG. 10, which is suitable for use in the method of the preferred embodiments, in plan view (not to scale). [0031]
  • FIG. 13 describes an embodiment of a cell suitable for use in the preferred embodiments in cross-section view on line 10-10 of FIG. 12 (not to scale). [0032]
  • FIG. 14 describes the cell of FIG. 10, which is suitable for use in the method of the preferred embodiments, in end section view (not to scale).[0033]
  • BEST MODE FOR CARRYING OUT THE INVENTION
  • In preferred embodiments of the method of the invention, glucose concentration is measured using an electrochemical cell of the kind described in PCT/AU96/00723 and/or PCT/AU96/00724 (our co-pending applications). The method of measurement described in those applications utilises an algorithm which enables the value of the diffusion coefficient of the redox mediator to be calculated and the concentration of reduced mediator to be determined in a manner which is substantially independent of sample temperature. The method therein described is different from prior art methods which measure Cottrell current at known times after application of a potential. The present invention differs in that the sample is heated. [0034]
  • In a first embodiment of the present method the blood sample is heated prior to and/or during conduct of the electrochemical measurement by means of an exothermic reaction. In the first embodiment a reagent that liberates heat on contact with blood is contained within the sensor cell. Examples of such reagents are salts which give out heat when they dissolve such as aluminium chloride, lithium halide salts, lithium sulphate, magnesium halide salts and magnesium sulphate. Another class of reagents which would be suitable are those with two components which liberate heat upon mixing. These two components would be placed in separate locations in the sensor during fabrication, for example on coatings upon opposite internal cell walls and are deployed such that when a sample is introduced into the sensor at least one of the components dissolves and then comes into contact with the second component. Upon contact the two components react to liberate heat. The reagents used to generate the heat must not adversely effect the function of the other active elements in the sensor. For instance, they must not corrode the electrode materials, denature an enzyme if present, or adversely interact with any mediator that may be present. Upon introducting a sample of blood into the sensor heat is liberated and the temperature of the blood sample is raised. This facilitates reaction of the glucose with the GDH and since the measurement of ferrocyanide concentration is temperature independent an accurate assessment of glucose concentration can be made in a much shorter time than would otherwise be possible. [0035]
  • Less preferably, the heat generating reagent can be added after the sample is admitted to the cell. [0036]
  • Preferably the sample temperature is raised by from 5 to 15° C., for example from 20° C. to 30° C. or 35° C. within a period of 2 to 10 seconds. The temperature peak is desirably reached within 2-5 seconds. [0037]
  • A second embodiment of the invention employs a cell in which an electrically resistive element is incorporated. The sample may then be electrically heated by passing a current through the resistive element. For example, with reference to FIG. 1 there is shown an electrochemical sensor comprising a plastic substrate [0038] 1 bearing a first electrode 2 (for example a sputtered layer of gold), a separator layer 3 having a circular aperture punched out which defines a cell volume 10 bounded on one cylindrical face by first electrode 2. The opposite face of cylindrical cell 10 is covered by a second electrode layer 4 (for example a sputter coating of palladium) which in this case is carried by a rubber or plastic layer 5. A metal foil layer 6 provides electrical contact to a resistive bridge 9 formed in the rubber or plastic layer 5. An insulating layer 7 for example of plastic provides insulation against heat loss through the metal foil. An aperture 8 in layer 7 provides for electrical contact with metal foil layer 6. Resistive bridge 9 is formed for example from carbon particles impregnated into the rubber or plastic of layer 5 at a loading and of a geometry such as to give a suitable electrical resistance between metal foil 6 and electrode layer 4. This method has the advantage of concentrating the heating effect adjacent the cell. Resistive heating elements may be fabricated by other means for example by coating an electrically conducting substrate with an electrically insulating layer which can be made partially conductive in particular regions if desired for example by exposure to particular chemicals and light. When using a cell according to the second embodiment the sample is admitted to the cell, a potential is applied across the resistive element, and after the required amount of heat has been generated the potential across the resistive element is interrupted and after an optional wait time a potential applied between the first electrode and second electrode to perform the electrochemical assay of the analyte.
  • Alternatively the potential across the resistive element can be maintained during the assay of the analyte at its initial level or at a lower level sufficient to substantially maintain the sample temperature at the desired level. [0039]
  • In another embodiment, the means for applying the potential to the resistive element is such that the current flowing through the resistive element is monitored and the potential automatically adjusted so as to maintain the required power output. This heats the sample in a reproducible fashion, even if the resistance of the resistive element varies from one sensor to the next. Furthermore, the power level required can be adjusted on the basis of the ambient temperature measured by a separate sensor. The leads to a more reproducible sample temperature being reached over a range of ambient temperature at which the sensor is being used. [0040]
  • In a third embodiment of the invention the sample is heated simply by applying an alternating voltage signal between the working and counter-electrodes of a sensor, for example, of the kind described in our co-pending applications. If this alternating voltage signal has a correct frequency and amplitude it will heat the sample while still allowing an accurate determination of the analyte to be subsequently made by the sensor. Because the voltage signal is alternating any reaction that occurs during one half voltage cycle is reversed during the second half of that cycle, resulting in no net change but in the dissipation of energy that will appear as heat in the sample. This is particularly applicable to sensors of the type disclosed in our abovementioned co-pending patent applications where any small changes that may occur in the cell are quickly removed after interruption of the alternating potential as the cell relaxes back to its initial stage. [0041]
  • When using cells such as described in our co-pending applications (see, e.g., FIGS. 12, 13, and [0042] 14), the sample volumes are very small and heating can be achieved with low energy input.
  • It is known to measure the concentration of a component to be analysed in an aqueous liquid sample by placing the sample into a reaction zone in an electrochemical cell comprising two electrodes having an impedance which renders them suitable for amperometric measurement. The component to be analysed is allowed to react directly with an electrode, or directly or indirectly with a redox reagent whereby to form an oxidisable (or reducible) substance in an amount corresponding to the concentration of the component to be analysed. The quantity of the oxidisable (or reducible) substance present is then estimated electrochemically. Generally this method requires sufficient separation of the electrodes so that electrolysis products at one electrode cannot reach the other electrode and interfere with the processes at the other electrode during the period of measurement. [0043]
  • In PCT/AU96/00365 is described a novel method for determining the concentration of the reduced (or oxidised) form of a redox species in an electrochemical cell of the kind comprising a working electrode and a counter (or counter/reference) electrode spaced from the working electrode. The method involves applying an electrical potential difference between the electrodes, spacing the working electrode from the counter electrode so that reaction products from the counter electrode arrive at the working electrode and selecting the potential of the working electrode so that the rate of electro-oxidation of the reduced form of the species (or of electro-reduction of the oxidised form) is diffusion controlled. By determining the current as a function of time after application of the potential and prior to achievement of a steady state current and then estimating the magnitude of the steady state current, the method previously described allows the diffusion coefficient and/or the concentration of the reduced (oxidised) form of the species to be estimated. [0044]
  • PCT/AU96/00365 exemplifies this method with reference to use of a “thin layer” cell employing a GOD/Ferrocyanide system. As herein used, the term “thin layer electrochemical cell” refers to a cell having closely spaced electrodes such that reaction products from the counter electrode arrive at the working electrode, in practice, the separation of electrodes in such a cell for measuring glucose in blood will be less than 500 microns, and preferably less than 200 microns. [0045]
  • The chemistry used in the exemplified electrochemical cell is as follows:[0046]
  • glucose+GOD→gluconic acid+GOD*  reaction 1
  • GOD*+2 ferricyanide→GOD+2 ferrocyanide  reaction 2
  • where GOD is the enzyme glucose oxidase and GOD* is the ‘activated’ enzyme. Ferricyanide ([Fe(CN)[0047] 6]3−) is the ‘mediator’ which returns the GOD* to its catalytic state. GOD, an enzyme catalyst, is not consumed during the reaction so long as excess mediator is present. Ferrocyanide ([Fe(CN)6]4−) is the product of the total reaction.
  • Ideally there is initially no ferrocyanide, although in practice there is often a small quantity. After reaction is complete the concentration of ferrocyanide (measured electrochemically) indicates the initial concentration of glucose. The total reaction is the sum of reactions 1 and 2:[0048]
  • GOD glucose+2 ferricyanide→gluconic acid+2 ferrocyanide  reaction 3
  • “Glucose” refers specifically to β-D-glucose. [0049]
  • The prior art suffers from a number of disadvantages. Firstly, sample size required is greater than desirable. It would be generally preferable to be able to make measurements on samples of reduced volume since this in turn enables use of less invasive methods to obtain samples. [0050]
  • Secondly, it would be generally desirable to the accuracy of measurement and to eliminate or reduce variations due, for example, to cell asymmetry or other factors introduced during mass production of microcells. [0051]
  • Thirdly, it would be generally desirable to reduce the time that is required in which to obtain a measurement. The test protocols used in current commercially available electrochemical glucose sensors involve a predetermined wait period at the beginning of the test during which the enzyme reacts with the glucose to produce the specie that is sensed electrochemically. This initial period is fixed at the maximum necessary to achieve the desired reaction under all conditions of use. [0052]
  • Fourthly, it would be desirable to eliminate variations due to oxygen. Oxygen can be plentiful in blood, either dissolved in the plasma, or bound in hemoglobin. It can also be introduced during “finger sticking,” where a blood drop of small volume and high surface area is exposed to the atmosphere prior to introduction to a cell. Oxygen can interfere since oxygen is a mediator for GOD. The reaction is as follows:[0053]
  • glucose+GOD→gluconic acid+GOD*  reaction 4
  • GOD*+oxygen+water→GOD+hydrogen peroxide  reaction 5
  • The total reaction is given by: [0054]
    Figure US20030080001A1-20030501-C00001
  • In most situations the complication of oxygen also acting as a mediator is unwanted simply because the concentration of final ferrocyanide no longer is directly proportional to the concentration of initial glucose. Instead, the initial glucose concentration is then related to both the final concentration of ferrocyanide and of hydrogen peroxide. [0055]
  • A method is provided for determining the concentration of a reduced (or oxidised) form of a redox species in an electrochemical cell of the kind comprising a working electrode and a counter electrode spaced from the working electrode by a predetermined distance, said method comprising the steps of: [0056]
  • (a) applying an electric potential between the electrodes, wherein the electrodes are spaced so that reaction products from the counter electrode arrive at the such that the rate of the electro-oxidation of the reduced form (or oxidised form) of the redox species is diffusion controlled, [0057]
  • (b) determining current as a function of time after application of the potential and prior to achievement of a steady state current, [0058]
  • (c) estimating the magnitude of the steady state current, [0059]
  • (d) interrupting, or reversing the polarity, of the potential, [0060]
  • (e) repeating step (b) and step (c). [0061]
  • It was discovered that if the polarity is reversed (i.e., the anode becomes the cathode and vice versa) after the initial steady state current is achieved, then a second transient current can be observed and after a period of time a second steady state is achieved. This has proved useful for diagnosing, and for reducing the effects of, cell asymmetry and other factors which influence the transient current. It also permits greater reliability and/or accuracy of estimation by allowing measurements to be made repetitively using reverse polarities. Likewise, if the potential is interrupted for a time sufficient for the concentration profile to relax to a random state and is then reapplied, steps (b) and (c) can be repeated. [0062]
  • A method is provided for measuring the concentration of glucose in a sample by means of a cell having a working electrode, a counter electrode, an enzyme catalyst, and a redox mediator, comprising the steps of operating the cell at a potential higher than that of the redox reaction so as to oxidise hydrogen peroxide at the anode and then conducting a method as described above. [0063]
  • By this means the interference of oxygen can be ameliorated as explained in more detail hereinafter. [0064]
  • A method is provided wherein the sample is allowed to react with an enzyme catalyst and a redox mediator comprising the steps of: [0065]
  • (a) applying a potential between the electrodes before or during filling of the cell, [0066]
  • (b) measuring the increase in current as a function of time, [0067]
  • (c) determining or predicting from the measurement in step (b) the time of completion of reaction with said catalyst, and [0068]
  • (d) then interrupting or reversing the polarity of the potential. [0069]
  • An electrochemical cell suitable for use in preferred embodiments is depicted schematically (not to scale) in FIGS. 12, 13, and [0070] 14. The cell comprises a polyester core 4 approximately 18 mm×5 mm and 100 micron thick and having a circular aperture 8 of 3.4 mm diameter. Aperture 8 defines a cylindrical cell side wall 10. Adhered to one side of core 4 is a polyester sheet 1 having a sputter coating of palladium 2. The sputter coating took place at between 4 and 6 millibar pressure in an atmosphere of argon gas to give a uniform coating thickness of 100-1000 angstroms. The sheet is adhered by means of an adhesive 3 to core 4 with palladium 2 adjacent core 4 and covering aperture 8.
  • A second polyester sheet [0071] 7 having a second sputter coating of palladium 6 is adhered by means of contact adhesive 5 to the other side of core 4 and covering aperture 8. There is thereby defined a cell having cylindrical side wall 10 and closed each end by palladium metal. The assembly is notched at 9 to provide for a solution to be admitted to the cell or to be drawn in by wicking or capillary action and to allow air to escape.
  • The metal films [0072] 2, 6 are connected with suitable electrical connections or formations whereby potentials may be applied and currently measured. The cell is furnished with GOD and ferrocyanide in dry form.
  • In use according to the method a drop of blood is drawn into the cell at [0073] 9 by capillary action and allowed to react.
  • The electrochemical means for measuring the ferrocyanide concentration after complete reaction can be considered by reference to FIG. 4. [0074]
  • In a thin layer cell the initial concentration of ferrocyanide and ferricyanide (after ‘enzymatic’ reaction is complete) is equal throughout the cell (the axis of interest being that between the electrodes). The concentration profile of ferrocyanide is given in FIG. 5. [0075]
  • When a particular potential is applied across the cell ferricyanide is converted to ferrocyanide at the cathode and ferrocyanide is converted to ferricyanide at the anode. [0076]
  • The chemistry is so arranged that after complete reaction there is still an excess of ferricyanide compared to ferrocyanide. For this reason the process that limits the complete electrochemical process is the conversion of ferrocyanide to ferricyanide at the anode, simply because ferrocyanide is at a significantly lower concentration. Further the rate limiting step for the reaction of ferrocyanide is the diffusion of ferrocyanide to the anode. After a period of time a steady-state is achieved, wherein the concentration profile of ferrocyanide and ferricyanide remains constant (see FIG. 5). [0077]
  • Therefore there are two limiting situations: initially [0078] 20 the ferrocyanide is evenly distributed throughout the cell. Then after a known potential is applied across the cell for a period of time a steady-state concentration profile of ferrocyanide is achieved. The ‘transient’ 22 reflects the measured cur-rent across the cell as the concentration adjusts from the initial situation to the final steady state situation 23. This is shown as a function of time in FIG. 6. It has been found that the change in the current with time during this ‘transient’ period is dependent upon the total concentration of ferrocyanide and the diffusion coefficient of ferrocyanide.
  • By solving the diffusion equations for this situation, it can be shown that the transient can be adequately described by the following equation over a restricted calculable time range. [0079] ln ( i i s - 1 ) = - 4 π 2 D t L 2 + ln ( 2 ) Eqn 1
    Figure US20030080001A1-20030501-M00001
  • where i is the measured current, i[0080] s is the current at steady-state, D the diffusion coefficient of ferrocyanide in the cell, L the separation distance between the anode and cathode, and t is time.
  • This is a simple solution of the general diffusion equation. However, it may be possible to use other solutions. [0081]
  • The final current at steady state also depends upon the total concentration of ferrocyanide and the diffusion coefficient of ferrocyanide. The steady state current can also be modeled by diffusion theory and is given by: [0082] i s s = 2 D F C A L Eqn 2
    Figure US20030080001A1-20030501-M00002
  • where F is the Faraday constant, C the initial concentration of ferrocyanide, and A the area of the working electrode. By initial concentration is meant the unperturbed concentration (shown as [0083] 20 in FIG. 5).
  • Analysis of the current observed during the transient and also at steady state allows calculation of both the concentration and diffusion coefficient of ferrocyanide, and thus also the initial glucose concentration. [0084]
  • This analysis is achieved by plotting: [0085] ln ( i i s - 1 ) Eqn 3
    Figure US20030080001A1-20030501-M00003
  • versus time which is substantially linear over a restricted and calculable time range and thus can be analysed for example by linear least squares regression. Since L is a constant for a given cell, measurement of i as a function of time and of i[0086] ss thus enables the value of the diffusion coefficient of the redox mediator to be calculated and the concentration of the analyte to be determined.
  • Another possible way to analyse the data is to use the variation of current with time soon after the potential step is applied to the electrodes. In this time period the current can be adequately described by the Cottrell equation. That is:[0087]
  • i−FAD ¼ C/(pi ½ t ½)  Eqn 4
  • By least squares regression on a plot of i versus 1/t[0088] ½ a value of FAD1/2C/pi½ can be estimated from the slope of this plot. The steady state current iss is given as before, so by combining the slope of the plot given above with the steady state current a value of the concentration of the ferrocyanide, independent of the diffusion coefficient of the ferrocyanide in the cell can be estimated. This is given by:
  • C=2slope2 pi/(FALi ss)  Eqn 5
  • In an example according to the preferred embodiments, a sample of blood is admitted to a thin layer cell containing a GOD/ferrocyanide system such as previously described with reference to FIGS. 12, 13, and [0089] 14. As illustrated in FIG. 6, after allowing a short time 20 for reaction, an electric potential is applied between the electrodes, current flow commences when the potential is applied 21 but then falls as a transient 22 towards a steady state level 23. The diffusion coefficient and/or glucose concentration are derived by measuring current as a function of time and by estimating the steady state current.
  • According to the preferred embodiments, the current is then interrupted, or reversed in polarity, for example by means of a suitable switch. If the polarity is reversed, a second transient is then observed, and a second steady state is reached after a further period of time although the profile is reversed. The underlying change in ferrocyanide concentration profile across the cell is shown schematically in FIG. 7. The initial concentration profile prior to current reversal is [0090] 23. The new steady state concentration profile is shown at 25. The transient concentration profiles are exemplified at 24.
  • By solving the diffusion equations for this situation, it can be shown that the transient current is described by. [0091] ln ( i i s - 1 ) = - 4 π 2 D t L 2 + ln ( 4 ) Eqn 6
    Figure US20030080001A1-20030501-M00004
  • It is therefore simple to re-estimate the diffusion coefficient and concentration under the reversed polarity conditions. In theory the results should be independent of the type of transient or polarity. In practice, the results may differ due to factors affecting the transient such as sample inhomogeneity, state of the electrodes, or more importantly, due to asymmetries in the cell construction. This measure is therefore useful for cell diagnosis and also enables greater accuracy by allowing repetitive measurement and averaging with reverse polarities. [0092]
  • Similarly, if the potential is interrupted after steady state is reached, the initial concentration profile will be re-established in a short time (for example 4 seconds). [0093]
  • Once the initial state is re-established (or approximated) the potential can be re-applied and the procedure repeated without current reversal. FIG. 9 shows a plot of current versus time similar to that of FIG. 6 but having the potential interrupted at [0094] 26 and reapplied after 15 seconds at 27 yielding a new transient current 28 and then a state 29.
  • As stated previously, the presence of oxygen in the blood is an interference since the concentration of final ferrocyanide is then not directly proportional to the initial glucose. Instead the initial glucose is related both to the final concentration of ferrocyanide plus hydrogen peroxide. However, it was found that hydrogen peroxide can be oxidised at the anode at a known potential which is higher than that for the ferrocyanide/ferricyanide redox reaction. The total electrochemical path is given in FIG. 10. The hydrogen peroxide reaction is:[0095]
  • hydrogen peroxide→oxygen+2 H++2e   reaction 7
  • If, during the period of enzyme reaction a potential is applied (FIG. 11) across the cell that is sufficient to oxidise hydrogen peroxide, then the following will happen during that period: [0096]
  • (a) glucose will be reacted to gluconic acid. [0097]
  • (b) ferrocyanide and hydrogen peroxide will result. [0098]
  • (c) the ferrocyanide/ferricyanide redox will eventually reach steady state. [0099]
  • (d) the peroxide will be oxidised at the anode and the electrons used to convert ferricyanide to ferrocyanide. [0100]
  • In total, after a period of time (approximately 2½ seconds in FIG. 11) at a constant potential all the peroxide will be converted to oxygen (which is then a catalyst, and will return to complete more enzyme chemistry until glucose is exhausted), and the electrons utilised to convert ferricyanide to ferrocyanide. [0101]
  • At this stage (60 seconds in FIG. 11) a reverse transient is applied. That is, the polarity of the cells is switched but now at the lower potential suitable for the ferricyanide/ferrocyanide redox reaction. The final steady state ferrocyanide will once again reflect the initial glucose concentration. This can be analysed in the previously described manner to determine the total concentration of glucose in the initial sample. [0102]
  • Using the method of the preferred embodiments, the reaction phase of the test can be monitored in situ electrochemically without interfering with the measurement phase. [0103]
  • When the reaction is complete one can proceed to measurement without further delay. [0104]
  • The wait time will vary from test to test and will be the minimum necessary for any particular sample and cell, taking account of changes in enzyme activity from cell to cell as well as different temperatures and glucose concentrations. This is in stark contrast to prior art in which measurement is delayed until the maximum time required for reaction after allowing for all these factors. [0105]
  • In the present method the reaction phase is monitored by applying a potential between the two electrodes of, for example, −300 mV as soon as the cell begins to fill with sample. [0106]
  • A linear concentration profile of the reduced mediator is soon achieved across the cell. As more reduced mediator is produced by the enzyme reaction with glucose this linear concentration profile becomes steeper and the current increases. When the reaction is complete the current no longer increases. This point can be detected by well known electronic means and the measurement phase of the test can then be commenced. [0107]
  • The end-point of the reaction can also be estimated by fitting a theoretical kinetic equation to the current versus time curve generated during this part of the test. [0108]
  • This equation can predict the degree of completion of the reaction at any time so would allow knowledge of when the end-point would occur without having to wait to get there. [0109]
  • This would further shorten the test time. For example, one could fit an equation to the measured prepulse current versus time curve. This equation could then predict that at time X the reaction will be, for example, 90% complete. If one measures the concentration at time X one would then divide the answer by 0.90 to get the true concentration. [0110]
  • The measurement of concentration in this system is done by reversing the potential, i.e. applying +300 mV between the electrodes. A current versus time curve will then occur, which is the same as that of the second transient in a double transient experiment le by transforming the current 1 measured during the measurement phase one can obtain a plot of ln(i/i[0111] ss−1) versus time which will have a slope of −4pi2D/l2 and an intercept ln(4). The normal analysis can then be used to obtain the concentration of glucose.
  • In some situations it may be difficult or impossible to know the distance between the electrodes in the electrochemical cell. For example, very small separations (ca. 10 microns) may be very difficult to manufacture or measure reproducibly. In these situations the use of information from two adjoining cells can be used to calculate the concentration of an analyte in a sample without knowledge of the cell separation if one of the cells contains a known concentration of the analyte or the corresponding reduced mediator prior to sample addition. Alternatively, a known quantity of this analyte or reduced mediator can be added to the sample destined for one of the two cells prior to addition of the sample to the cell. Another variation is if both cells contain a pre-determined analyte or reduced mediator concentration but each has a different concentration. Yet another variation is if two different predetermined quantities of the analyte or reduced mediator are added to two aliquots of the sample, which are then added to the adjoining cells. [0112]
  • The two electrochemical cells are then used in the normal fashion, and from each cell the following quantities are measured: steady state current (i[0113] ss) and the slope of the straight line defined by ln(i/iss−1) versus time, where i is the measured current. With a knowledge of these values and also a knowledge of the difference in concentration of the analyte or reduced mediator between the two cells, which is known (it is equal to that value purposely added to one cell), it is possible to calculate the concentration of analyte or reduced mediator in the sample, without any knowledge of the separation distance of the electrodes.
  • The above can be used in conjunction with a third cell that is used to measure the background current or concentration due to current caused by, for example, reduced mediator formed by the application and drying of the chemistry, catalytic effect of the metal surface, oxidation of the metal surface, sample components that have effects on the analyte or mediator, electrochemically responsive components of the sample etc. This background concentration or current would be subtracted from the values measured from the two cells discussed above to calculate the true values for each cell resulting from the analyte in the sample, and in one case also the analyte or reduced mediator purposely added to the cell or the sample. [0114]
  • As will be apparent to those skilled in the art, from the teaching hereof the method is suitable for use with automatic measuring apparatus. Cells of the kind described may be provided with electrical connectors to an apparatus provide with a microprocessor or other programmed electronic control and display circuits which are adapted to make the required measurements perform the required calculations and to display the result. The method may be used to measure the concentration of analytes other than glucose and in liquids other than blood. [0115]
  • The method may be conducted using cells of other design and/or construction and using known catalysts and redox systems other than that exemplified. [0116]
  • EXAMPLES OF HEATED STRIP EXPERIMENTS Example 1
  • Disposable test strips of the type described in PCT/AU96/00724 were heated by placing a metal bar, heated to 50° C., in contact with the sample receiving area of the strip. Whole blood samples were introduced into the sample receiving area of the strip and 13 seconds allowed for the glucose present in the sample to react with the sensor reagents. Current was then collected for ten seconds and analyzed according to the methods described in PCT/AU96/00723. The results of these tests for blood samples with maematocrits of 67.5%, 49.5% and 20% and glucose concentrations between 2.5 mM and 30 mM are shown in FIG. 2. [0117]
  • Example 1
  • Disposable test strips of the type described in PCT/AU96/00724 were modified by adhering a heater element to the base of the strip, beneath the sample receiving area. The heater element was fabricated by sputtering two parallel low resistance metallic tracks onto a polyester substrate and then sputtering a thin, resistive metallic track at right angles to the low resistance metallic tracks, such that the resistive metallic track contacted both of the parallel low resistance tracks. This heater was then glued to the base of the disposable test strip using an adhesive, such that the resistive track was positioned directly beneath and facing the sample receiving area on the strip. The parallel low resistance tracks protruded from the end of the strip and provided electrical contacts for a power supply to power the heater. The power supply for the heater consisted of a battery and a variable resistor, which could be adjusted to vary the rate of heating. Whole blood samples were introduced into the sample receiving area of the strip and 20 seconds allowed for the glucose present in the sample to react with the sensor reagents. Current was then collected for ten seconds and analyzed according to the methods described in PCT/AU96/00723. The results of these tests for blood samples with haematocrits of 65%, 46% and 20% and glucose concentrations between 2.8 mM and 32.5 mM are shown in FIG. 3. [0118]
  • Although the invention has been herein described with reference to electrochemical methods for measuring glucose concentration in blood it will be appreciated that the method may also be applied utilising suitable spectroscopic or other measuring methods and samples other than blood and to analytes other than glucose. [0119]

Claims (27)

What is claimed is:
1. A method for determining a concentration of an analyte in a sample comprising the steps of:
heating the sample in a disposable test cell; and
measuring the concentration of the analyte or a concentration of a species representative of the analyte in the sample at a predetermined point on a reaction profile by means that are substantially independent of the temperature of the sample in the test cell.
2. The method according to claim 1 wherein the predetermined point on the reaction profile is a steady state.
3. The method according to claim 1 wherein the species representative of the concentration of the analyte is a mediator.
4. The method according to claim 3 wherein the mediator is an enzyme mediator.
5. The method according to claim 1 wherein the sample is heated by an exothermic reaction produced upon contact of said sample with at least one suitable reagent.
6. The method according to claim 5 wherein the at least one suitable reagent is a salt which liberates heat on dissolution.
7. The method according to claim 6 wherein the salts are selected from the group consisting of aluminium chloride, lithium halides, lithium sulfate, magnesium halides, and magnesium sulfate.
8. The method according to claim 5 wherein the at least one suitable reagent is a two component system which liberates heat upon mixing.
9. The method according to claim 8 wherein each of the two components are placed in separate locations in a sensor during fabrication.
10. The method according to claim 9 wherein said two components are placed as coatings upon opposite internal cell walls of a sensor.
11. The method according to claim 1 wherein the sample is heated electrically.
12. The method according to claim 11 wherein said sample is heated by means of a current applied to resistive elements associated with said measuring means.
13. The method according to claim 1 wherein the concentration of the analyte is measured by an electrochemical measurement.
14. The method according to claim 13 wherein the sample is heated prior to and/or during conduct of the electrochemical measurement.
15. The method according to claim 1 wherein the sample temperature is raised by from 5 to 15° C.
16. The method according to claim 1 wherein the sample temperature is raised within a period of 2-10 seconds.
17. The method according to claim 1 wherein a peak temperature is reached with 2-5 seconds.
18. The method according to claim 1 wherein the analyte is glucose.
19. The method according to claim 1 wherein the sample is blood.
20. The method according to claim 19 wherein the blood sample is combined with an enzyme.
21. The method according to claim 20 wherein the enzyme is glucose dehydrogenase (GDH) which oxidises glucose and is converted to reduced GDH.
22. The method according to claim 21 wherein an oxidising mediator is present.
23. The method according to claim 22 wherein said oxidising mediator is ferricyanide.
24. The method according to claim 23 wherein said ferricyanide reacts with said produced GDH to produce ferrocyanide.
25. The method according to claim 24 wherein the ferrocyanide produced is sensed to produce a signal representative of the glucose concentration of the sample.
26. The method according to claim 25 wherein the sensing is by electrochemical means.
27. The method according to claim 25 wherein the sensing is by a spectroscopic means.
US10/246,370 1998-03-12 2002-09-16 Heated electrochemical cell Abandoned US20030080001A1 (en)

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US09/659,470 US6475360B1 (en) 1998-03-12 2000-09-11 Heated electrochemical cell
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Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070246357A1 (en) * 2004-10-12 2007-10-25 Huan-Ping Wu Concentration Determination in a Diffusion Barrier Layer
US7645373B2 (en) 2003-06-20 2010-01-12 Roche Diagnostic Operations, Inc. System and method for coding information on a biosensor test strip
US7645421B2 (en) 2003-06-20 2010-01-12 Roche Diagnostics Operations, Inc. System and method for coding information on a biosensor test strip
US7718439B2 (en) 2003-06-20 2010-05-18 Roche Diagnostics Operations, Inc. System and method for coding information on a biosensor test strip
US8058077B2 (en) 2003-06-20 2011-11-15 Roche Diagnostics Operations, Inc. Method for coding information on a biosensor test strip
US8071384B2 (en) 1997-12-22 2011-12-06 Roche Diagnostics Operations, Inc. Control and calibration solutions and methods for their use
US8092668B2 (en) 2004-06-18 2012-01-10 Roche Diagnostics Operations, Inc. System and method for quality assurance of a biosensor test strip
US8148164B2 (en) 2003-06-20 2012-04-03 Roche Diagnostics Operations, Inc. System and method for determining the concentration of an analyte in a sample fluid
US8206565B2 (en) 2003-06-20 2012-06-26 Roche Diagnostics Operation, Inc. System and method for coding information on a biosensor test strip
US8663442B2 (en) 2003-06-20 2014-03-04 Roche Diagnostics Operations, Inc. System and method for analyte measurement using dose sufficiency electrodes

Families Citing this family (64)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3394262B2 (en) 1997-02-06 2003-04-07 イー.ヘラー アンド カンパニー Small volume in vitro analyte sensor
US6036924A (en) 1997-12-04 2000-03-14 Hewlett-Packard Company Cassette of lancet cartridges for sampling blood
US6391005B1 (en) 1998-03-30 2002-05-21 Agilent Technologies, Inc. Apparatus and method for penetration with shaft having a sensor for sensing penetration depth
US6338790B1 (en) 1998-10-08 2002-01-15 Therasense, Inc. Small volume in vitro analyte sensor with diffusible or non-leachable redox mediator
US8641644B2 (en) 2000-11-21 2014-02-04 Sanofi-Aventis Deutschland Gmbh Blood testing apparatus having a rotatable cartridge with multiple lancing elements and testing means
US7892183B2 (en) 2002-04-19 2011-02-22 Pelikan Technologies, Inc. Method and apparatus for body fluid sampling and analyte sensing
US7976476B2 (en) 2002-04-19 2011-07-12 Pelikan Technologies, Inc. Device and method for variable speed lancet
US7229458B2 (en) 2002-04-19 2007-06-12 Pelikan Technologies, Inc. Method and apparatus for penetrating tissue
US7901362B2 (en) 2002-04-19 2011-03-08 Pelikan Technologies, Inc. Method and apparatus for penetrating tissue
US7682318B2 (en) 2001-06-12 2010-03-23 Pelikan Technologies, Inc. Blood sampling apparatus and method
US7699791B2 (en) 2001-06-12 2010-04-20 Pelikan Technologies, Inc. Method and apparatus for improving success rate of blood yield from a fingerstick
US7297122B2 (en) 2002-04-19 2007-11-20 Pelikan Technologies, Inc. Method and apparatus for penetrating tissue
EP1404233B1 (en) 2001-06-12 2009-12-02 Pelikan Technologies Inc. Self optimizing lancing device with adaptation means to temporal variations in cutaneous properties
US7232451B2 (en) 2002-04-19 2007-06-19 Pelikan Technologies, Inc. Method and apparatus for penetrating tissue
US9248267B2 (en) 2002-04-19 2016-02-02 Sanofi-Aventis Deustchland Gmbh Tissue penetration device
US7717863B2 (en) 2002-04-19 2010-05-18 Pelikan Technologies, Inc. Method and apparatus for penetrating tissue
WO2002100254A2 (en) 2001-06-12 2002-12-19 Pelikan Technologies, Inc. Method and apparatus for lancet launching device integrated onto a blood-sampling cartridge
US7547287B2 (en) 2002-04-19 2009-06-16 Pelikan Technologies, Inc. Method and apparatus for penetrating tissue
US7981056B2 (en) 2002-04-19 2011-07-19 Pelikan Technologies, Inc. Methods and apparatus for lancet actuation
US7674232B2 (en) 2002-04-19 2010-03-09 Pelikan Technologies, Inc. Method and apparatus for penetrating tissue
US9226699B2 (en) 2002-04-19 2016-01-05 Sanofi-Aventis Deutschland Gmbh Body fluid sampling module with a continuous compression tissue interface surface
US9427532B2 (en) 2001-06-12 2016-08-30 Sanofi-Aventis Deutschland Gmbh Tissue penetration device
US7226461B2 (en) 2002-04-19 2007-06-05 Pelikan Technologies, Inc. Method and apparatus for a multi-use body fluid sampling device with sterility barrier release
US7291117B2 (en) 2002-04-19 2007-11-06 Pelikan Technologies, Inc. Method and apparatus for penetrating tissue
US8337419B2 (en) 2002-04-19 2012-12-25 Sanofi-Aventis Deutschland Gmbh Tissue penetration device
US7344507B2 (en) 2002-04-19 2008-03-18 Pelikan Technologies, Inc. Method and apparatus for lancet actuation
US8579831B2 (en) 2002-04-19 2013-11-12 Sanofi-Aventis Deutschland Gmbh Method and apparatus for penetrating tissue
US9795334B2 (en) 2002-04-19 2017-10-24 Sanofi-Aventis Deutschland Gmbh Method and apparatus for penetrating tissue
US7491178B2 (en) 2002-04-19 2009-02-17 Pelikan Technologies, Inc. Method and apparatus for penetrating tissue
US7909778B2 (en) 2002-04-19 2011-03-22 Pelikan Technologies, Inc. Method and apparatus for penetrating tissue
US7041068B2 (en) 2001-06-12 2006-05-09 Pelikan Technologies, Inc. Sampling module device and method
WO2002100460A2 (en) 2001-06-12 2002-12-19 Pelikan Technologies, Inc. Electric lancet actuator
US7331931B2 (en) 2002-04-19 2008-02-19 Pelikan Technologies, Inc. Method and apparatus for penetrating tissue
US7371247B2 (en) 2002-04-19 2008-05-13 Pelikan Technologies, Inc Method and apparatus for penetrating tissue
US7648468B2 (en) 2002-04-19 2010-01-19 Pelikon Technologies, Inc. Method and apparatus for penetrating tissue
US9314194B2 (en) 2002-04-19 2016-04-19 Sanofi-Aventis Deutschland Gmbh Tissue penetration device
US8221334B2 (en) 2002-04-19 2012-07-17 Sanofi-Aventis Deutschland Gmbh Method and apparatus for penetrating tissue
US8267870B2 (en) 2002-04-19 2012-09-18 Sanofi-Aventis Deutschland Gmbh Method and apparatus for body fluid sampling with hybrid actuation
US8784335B2 (en) 2002-04-19 2014-07-22 Sanofi-Aventis Deutschland Gmbh Body fluid sampling device with a capacitive sensor
US8702624B2 (en) 2006-09-29 2014-04-22 Sanofi-Aventis Deutschland Gmbh Analyte measurement device with a single shot actuator
US8574895B2 (en) 2002-12-30 2013-11-05 Sanofi-Aventis Deutschland Gmbh Method and apparatus using optical techniques to measure analyte levels
US7850621B2 (en) 2003-06-06 2010-12-14 Pelikan Technologies, Inc. Method and apparatus for body fluid sampling and analyte sensing
WO2005033659A2 (en) 2003-09-29 2005-04-14 Pelikan Technologies, Inc. Method and apparatus for an improved sample capture device
WO2005037095A1 (en) 2003-10-14 2005-04-28 Pelikan Technologies, Inc. Method and apparatus for a variable user interface
WO2005065414A2 (en) 2003-12-31 2005-07-21 Pelikan Technologies, Inc. Method and apparatus for improving fluidic flow and sample capture
EP1751546A2 (en) 2004-05-20 2007-02-14 Albatros Technologies GmbH & Co. KG Printable hydrogel for biosensors
CN103353475B (en) * 2004-05-21 2017-03-01 埃葛梅崔克斯股份有限公司 The electrochemical cell and method for producing an electrochemical cell
EP1765194A4 (en) 2004-06-03 2010-09-29 Pelikan Technologies Inc Method and apparatus for a fluid sampling device
WO2006001797A1 (en) 2004-06-14 2006-01-05 Pelikan Technologies, Inc. Low pain penetrating
US8652831B2 (en) 2004-12-30 2014-02-18 Sanofi-Aventis Deutschland Gmbh Method and apparatus for analyte measurement test time
US7822454B1 (en) 2005-01-03 2010-10-26 Pelikan Technologies, Inc. Fluid sampling device with improved analyte detecting member configuration
US20070235346A1 (en) * 2006-04-11 2007-10-11 Popovich Natasha D System and methods for providing corrected analyte concentration measurements
US7909983B2 (en) * 2006-05-04 2011-03-22 Nipro Diagnostics, Inc. System and methods for automatically recognizing a control solution
US20080273572A1 (en) * 2006-06-02 2008-11-06 James Madison University Thermal detector for chemical or biological agents
JPWO2008136472A1 (en) * 2007-04-29 2010-07-29 アークレイ株式会社 Analysis system
CN101320035A (en) * 2007-05-21 2008-12-10 台达电子工业股份有限公司 Biological sensor and its composite
JP2009103519A (en) * 2007-10-22 2009-05-14 Panasonic Corp Apparatus and method for detecting or measuring existence of biological specific reactant
WO2009126900A1 (en) 2008-04-11 2009-10-15 Pelikan Technologies, Inc. Method and apparatus for analyte detecting device
US9375169B2 (en) 2009-01-30 2016-06-28 Sanofi-Aventis Deutschland Gmbh Cam drive for managing disposable penetrating member actions with a single motor and motor and control system
TWI388823B (en) * 2009-04-09 2013-03-11 Bionime Corp A method for estimating the distribution of a sample
US8101065B2 (en) * 2009-12-30 2012-01-24 Lifescan, Inc. Systems, devices, and methods for improving accuracy of biosensors using fill time
US8965476B2 (en) 2010-04-16 2015-02-24 Sanofi-Aventis Deutschland Gmbh Tissue penetration device
US9795747B2 (en) 2010-06-02 2017-10-24 Sanofi-Aventis Deutschland Gmbh Methods and apparatus for lancet actuation
US10144949B2 (en) 2015-12-28 2018-12-04 Polymer Technology Systems, Inc. Systems and methods for electrochemical aspartate transaminase (AST) and alanine transaminase (ALT) detection and quantification

Citations (68)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3616411A (en) * 1968-09-16 1971-10-26 Gen Electric Partial pressure sensor
US4053381A (en) * 1976-05-19 1977-10-11 Eastman Kodak Company Device for determining ionic activity of components of liquid drops
US4076596A (en) * 1976-10-07 1978-02-28 Leeds & Northrup Company Apparatus for electrolytically determining a species in a fluid and method of use
US4100048A (en) * 1973-09-20 1978-07-11 U.S. Philips Corporation Polarographic cell
US4224125A (en) * 1977-09-28 1980-09-23 Matsushita Electric Industrial Co., Ltd. Enzyme electrode
US4301412A (en) * 1979-10-29 1981-11-17 United States Surgical Corporation Liquid conductivity measuring system and sample cards therefor
US4301414A (en) * 1979-10-29 1981-11-17 United States Surgical Corporation Disposable sample card and method of making same
US4303887A (en) * 1979-10-29 1981-12-01 United States Surgical Corporation Electrical liquid conductivity measuring system
US4319969A (en) * 1979-08-31 1982-03-16 Asahi Glass Company, Ltd. Aqueous alkali metal chloride electrolytic cell
US4374013A (en) * 1980-03-05 1983-02-15 Enfors Sven Olof Oxygen stabilized enzyme electrode
US4404066A (en) * 1980-08-25 1983-09-13 The Yellow Springs Instrument Company Method for quantitatively determining a particular substrate catalyzed by a multisubstrate enzyme
US4431507A (en) * 1981-01-14 1984-02-14 Matsushita Electric Industrial Co., Ltd. Enzyme electrode
US4431004A (en) * 1981-10-27 1984-02-14 Bessman Samuel P Implantable glucose sensor
US4508613A (en) * 1983-12-19 1985-04-02 Gould Inc. Miniaturized potassium ion sensor
US4517291A (en) * 1983-08-15 1985-05-14 E. I. Du Pont De Nemours And Company Biological detection process using polymer-coated electrodes
US4533440A (en) * 1983-08-04 1985-08-06 General Electric Company Method for continuous measurement of the sulfite/sulfate ratio
US4545382A (en) * 1981-10-23 1985-10-08 Genetics International, Inc. Sensor for components of a liquid mixture
US4552840A (en) * 1982-12-02 1985-11-12 California And Hawaiian Sugar Company Enzyme electrode and method for dextran analysis
US4654197A (en) * 1983-10-18 1987-03-31 Aktiebolaget Leo Cuvette for sampling and analysis
US4664119A (en) * 1985-12-04 1987-05-12 University Of Southern California Transcutaneous galvanic electrode oxygen sensor
US4711245A (en) * 1983-05-05 1987-12-08 Genetics International, Inc. Sensor for components of a liquid mixture
US4790925A (en) * 1987-09-18 1988-12-13 Mine Safety Appliances Company Electrochemical gas sensor
US4874501A (en) * 1985-06-18 1989-10-17 Radiometer A/S Membrane for an electrochemical measuring electrode device
US4897173A (en) * 1985-06-21 1990-01-30 Matsushita Electric Industrial Co., Ltd. Biosensor and method for making the same
US4900424A (en) * 1986-11-28 1990-02-13 Unilever Patent Holdings B.V. Electrochemical measurement cell
US4919770A (en) * 1982-07-30 1990-04-24 Siemens Aktiengesellschaft Method for determining the concentration of electro-chemically convertible substances
US4935345A (en) * 1987-04-07 1990-06-19 Arizona Board Of Regents Implantable microelectronic biochemical sensor incorporating thin film thermopile
US4963815A (en) * 1987-07-10 1990-10-16 Molecular Devices Corporation Photoresponsive electrode for determination of redox potential
US4988429A (en) * 1989-06-30 1991-01-29 Dragerwerk Aktiengesellschaft Measuring cell for an electrochemical gas sensor
US5059908A (en) * 1990-05-31 1991-10-22 Capital Controls Company, Inc. Amperimetric measurement with cell electrode deplating
US5064516A (en) * 1987-07-16 1991-11-12 Gas Research Institute Measuring gas levels
US5108564A (en) * 1988-03-15 1992-04-28 Tall Oak Ventures Method and apparatus for amperometric diagnostic analysis
US5120420A (en) * 1988-03-31 1992-06-09 Matsushita Electric Industrial Co., Ltd. Biosensor and a process for preparation thereof
US5122244A (en) * 1990-02-03 1992-06-16 Boehringer Mannheim Gmbh Method and sensor electrode system for the electrochemical determination of an analyte or an oxidoreductase as well as the use of suitable compounds therefor
US5126034A (en) * 1988-07-21 1992-06-30 Medisense, Inc. Bioelectrochemical electrodes
US5128015A (en) * 1988-03-15 1992-07-07 Tall Oak Ventures Method and apparatus for amperometric diagnostic analysis
US5141868A (en) * 1984-06-13 1992-08-25 Internationale Octrooi Maatschappij "Octropa" Bv Device for use in chemical test procedures
US5185256A (en) * 1985-06-21 1993-02-09 Matsushita Electric Industrial Co., Ltd. Method for making a biosensor
US5192415A (en) * 1991-03-04 1993-03-09 Matsushita Electric Industrial Co., Ltd. Biosensor utilizing enzyme and a method for producing the same
US5229282A (en) * 1989-11-24 1993-07-20 Matsushita Electric Industrial Co., Ltd. Preparation of biosensor having a layer containing an enzyme, electron acceptor and hydrophilic polymer on an electrode system
US5264103A (en) * 1991-10-18 1993-11-23 Matsushita Electric Industrial Co., Ltd. Biosensor and a method for measuring a concentration of a substrate in a sample
US5266179A (en) * 1990-07-20 1993-11-30 Matsushita Electric Industrial Co., Ltd. Quantitative analysis method and its system using a disposable sensor
US5272087A (en) * 1988-04-20 1993-12-21 Centre National De La Recherche Scientifique (C.N.R.S.) Enzymatic electrode and its preparation method
US5312590A (en) * 1989-04-24 1994-05-17 National University Of Singapore Amperometric sensor for single and multicomponent analysis
US5314605A (en) * 1989-06-30 1994-05-24 Dragerwerk Aktiengesellschaft Measuring cell for electrochemically detecting a gas
US5320732A (en) * 1990-07-20 1994-06-14 Matsushita Electric Industrial Co., Ltd. Biosensor and measuring apparatus using the same
US5382346A (en) * 1991-05-17 1995-01-17 Kyoto Daiichi Kagaku Co., Ltd. Biosensor and method of quantitative analysis using the same
US5384028A (en) * 1992-08-28 1995-01-24 Nec Corporation Biosensor with a data memory
US5385846A (en) * 1993-06-03 1995-01-31 Boehringer Mannheim Corporation Biosensor and method for hematocrit determination
US5393399A (en) * 1992-09-07 1995-02-28 Gie Cylergie Amperometric measuring device having an electrochemical sensor
US5405511A (en) * 1993-06-08 1995-04-11 Boehringer Mannheim Corporation Biosensing meter with ambient temperature estimation method and system
US5413690A (en) * 1993-07-23 1995-05-09 Boehringer Mannheim Corporation Potentiometric biosensor and the method of its use
US5437999A (en) * 1994-02-22 1995-08-01 Boehringer Mannheim Corporation Electrochemical sensor
US5502396A (en) * 1993-09-21 1996-03-26 Asulab S.A. Measuring device with connection for a removable sensor
US5508171A (en) * 1989-12-15 1996-04-16 Boehringer Mannheim Corporation Assay method with enzyme electrode system
US5509410A (en) * 1983-06-06 1996-04-23 Medisense, Inc. Strip electrode including screen printing of a single layer
US5512159A (en) * 1992-01-21 1996-04-30 Matsushita Electric Industrial Co. Ltd. Biosensor
US5518590A (en) * 1994-06-21 1996-05-21 Pennzoil Products Company Electrochemical sensors for motor oils and other lubricants
US5520787A (en) * 1994-02-09 1996-05-28 Abbott Laboratories Diagnostic flow cell device
US5527446A (en) * 1995-04-13 1996-06-18 United States Of America As Represented By The Secretary Of The Air Force Gas sensor
US5567302A (en) * 1995-06-07 1996-10-22 Molecular Devices Corporation Electrochemical system for rapid detection of biochemical agents that catalyze a redox potential change
US5607565A (en) * 1995-03-27 1997-03-04 Coulter Corporation Apparatus for measuring analytes in a fluid sample
US5620579A (en) * 1995-05-05 1997-04-15 Bayer Corporation Apparatus for reduction of bias in amperometric sensors
US5628890A (en) * 1995-09-27 1997-05-13 Medisense, Inc. Electrochemical sensor
US5645709A (en) * 1993-12-08 1997-07-08 Van Den Bergh Foods Co., Division Of Conopco, Inc. Methods and apparatus for electrochemical measurements
US5846422A (en) * 1994-03-04 1998-12-08 Memtec America Corporation Large pore synthetic polymer membranes
US5942102A (en) * 1995-11-16 1999-08-24 Usf Filtration And Separations Group Inc. Electrochemical method
US5997817A (en) * 1997-12-05 1999-12-07 Roche Diagnostics Corporation Electrochemical biosensor test strip

Family Cites Families (28)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA1133059A (en) 1978-10-25 1982-10-05 Richard L. Columbus Electrode-containing device with capillary transport between electrodes
CA1153580A (en) 1979-10-29 1983-09-13 Jeremy R. Hill Liquid conductivity measuring system and sample cards therefor
US4819054A (en) * 1982-09-29 1989-04-04 Hitachi, Ltd. Semiconductor IC with dual groove isolation
CA1226036A (en) 1983-05-05 1987-08-25 Irving J. Higgins Analytical equipment and sensor electrodes therefor
JPH0419503B2 (en) 1986-06-27 1992-03-30 Terumo Corp
GB8618022D0 (en) 1986-07-23 1986-08-28 Unilever Plc Electrochemical measurements
EP0278647A3 (en) 1987-02-09 1989-09-20 AT&T Corp. Electronchemical processes involving enzymes
GB2201248B (en) 1987-02-24 1991-04-17 Ici Plc Enzyme electrode sensors
GB8709882D0 (en) 1987-04-27 1987-06-03 Genetics Int Inc Membrane configurations
US4812221A (en) 1987-07-15 1989-03-14 Sri International Fast response time microsensors for gaseous and vaporous species
GB2215846B (en) 1988-03-23 1992-04-22 Nat Res Dev Method and apparatus for measuring the type and concentration of ion species in liquids
CA1316572C (en) 1988-07-18 1993-04-20 Martin J. Patko Precalibrated, disposable, electrochemical sensors
US5236567A (en) 1989-05-31 1993-08-17 Nakano Vinegar Co., Ltd. Enzyme sensor
GB2235050B (en) 1989-08-14 1994-01-05 Sieger Ltd Electrochemical gas sensor
DE4026017A1 (en) * 1990-08-17 1992-02-20 Hoechst Ag A process for preparing formkoerpern from precursors of high temperature superconductors
AU3104293A (en) 1992-01-14 1993-07-15 Commonwealth Scientific And Industrial Research Organisation Viscometer
JPH0634600A (en) 1992-07-22 1994-02-08 Daikin Ind Ltd Catalase activity measuring apparatus
GB9215972D0 (en) 1992-07-28 1992-09-09 Univ Manchester Improved analytical method
EP0585933B1 (en) 1992-09-04 2005-12-21 Matsushita Electric Industrial Co., Ltd. Planar electrode
FR2701117B1 (en) 1993-02-04 1995-03-10 Asulab Sa System of electrochemical measurement multizone sensor, and its application to glucose analysis.
DE4312126A1 (en) 1993-04-14 1994-10-20 Mannesmann Ag Gas diffusion electrode for electrochemical cells
DE4341796A1 (en) 1993-12-08 1995-09-14 Bosch Gmbh Robert Method for controlling the combustion in the combustion chamber of an internal combustion engine
GB9402591D0 (en) 1994-02-10 1994-04-06 Univ Cranfield Hexacyanoferrate (III) modified carbon electrodes
JPH0862179A (en) 1995-02-13 1996-03-08 Hitachi Instr Eng Co Ltd Electrolyte analyzer
US5665215A (en) 1995-09-25 1997-09-09 Bayer Corporation Method and apparatus for making predetermined events with a biosensor
DE29709141U1 (en) 1997-05-24 1997-08-28 Kurt Schwabe Inst Fuer Mes Und Membrane-covered electrochemical gas sensor
US6475360B1 (en) * 1998-03-12 2002-11-05 Lifescan, Inc. Heated electrochemical cell
JP3874321B2 (en) 1998-06-11 2007-01-31 松下電器産業株式会社 Biosensor

Patent Citations (70)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3616411A (en) * 1968-09-16 1971-10-26 Gen Electric Partial pressure sensor
US4100048A (en) * 1973-09-20 1978-07-11 U.S. Philips Corporation Polarographic cell
US4053381A (en) * 1976-05-19 1977-10-11 Eastman Kodak Company Device for determining ionic activity of components of liquid drops
US4076596A (en) * 1976-10-07 1978-02-28 Leeds & Northrup Company Apparatus for electrolytically determining a species in a fluid and method of use
US4224125A (en) * 1977-09-28 1980-09-23 Matsushita Electric Industrial Co., Ltd. Enzyme electrode
US4319969A (en) * 1979-08-31 1982-03-16 Asahi Glass Company, Ltd. Aqueous alkali metal chloride electrolytic cell
US4301412A (en) * 1979-10-29 1981-11-17 United States Surgical Corporation Liquid conductivity measuring system and sample cards therefor
US4301414A (en) * 1979-10-29 1981-11-17 United States Surgical Corporation Disposable sample card and method of making same
US4303887A (en) * 1979-10-29 1981-12-01 United States Surgical Corporation Electrical liquid conductivity measuring system
US4374013A (en) * 1980-03-05 1983-02-15 Enfors Sven Olof Oxygen stabilized enzyme electrode
US4404066A (en) * 1980-08-25 1983-09-13 The Yellow Springs Instrument Company Method for quantitatively determining a particular substrate catalyzed by a multisubstrate enzyme
US4431507A (en) * 1981-01-14 1984-02-14 Matsushita Electric Industrial Co., Ltd. Enzyme electrode
US4545382A (en) * 1981-10-23 1985-10-08 Genetics International, Inc. Sensor for components of a liquid mixture
US4431004A (en) * 1981-10-27 1984-02-14 Bessman Samuel P Implantable glucose sensor
US4919770A (en) * 1982-07-30 1990-04-24 Siemens Aktiengesellschaft Method for determining the concentration of electro-chemically convertible substances
US4552840A (en) * 1982-12-02 1985-11-12 California And Hawaiian Sugar Company Enzyme electrode and method for dextran analysis
US4711245A (en) * 1983-05-05 1987-12-08 Genetics International, Inc. Sensor for components of a liquid mixture
US5509410A (en) * 1983-06-06 1996-04-23 Medisense, Inc. Strip electrode including screen printing of a single layer
US4533440A (en) * 1983-08-04 1985-08-06 General Electric Company Method for continuous measurement of the sulfite/sulfate ratio
US4517291A (en) * 1983-08-15 1985-05-14 E. I. Du Pont De Nemours And Company Biological detection process using polymer-coated electrodes
US4654197A (en) * 1983-10-18 1987-03-31 Aktiebolaget Leo Cuvette for sampling and analysis
US4508613A (en) * 1983-12-19 1985-04-02 Gould Inc. Miniaturized potassium ion sensor
US5141868A (en) * 1984-06-13 1992-08-25 Internationale Octrooi Maatschappij "Octropa" Bv Device for use in chemical test procedures
US4874501A (en) * 1985-06-18 1989-10-17 Radiometer A/S Membrane for an electrochemical measuring electrode device
US4897173A (en) * 1985-06-21 1990-01-30 Matsushita Electric Industrial Co., Ltd. Biosensor and method for making the same
US5185256A (en) * 1985-06-21 1993-02-09 Matsushita Electric Industrial Co., Ltd. Method for making a biosensor
US4664119A (en) * 1985-12-04 1987-05-12 University Of Southern California Transcutaneous galvanic electrode oxygen sensor
US4900424A (en) * 1986-11-28 1990-02-13 Unilever Patent Holdings B.V. Electrochemical measurement cell
US4935345A (en) * 1987-04-07 1990-06-19 Arizona Board Of Regents Implantable microelectronic biochemical sensor incorporating thin film thermopile
US4963815A (en) * 1987-07-10 1990-10-16 Molecular Devices Corporation Photoresponsive electrode for determination of redox potential
US5064516A (en) * 1987-07-16 1991-11-12 Gas Research Institute Measuring gas levels
US4790925A (en) * 1987-09-18 1988-12-13 Mine Safety Appliances Company Electrochemical gas sensor
US5108564A (en) * 1988-03-15 1992-04-28 Tall Oak Ventures Method and apparatus for amperometric diagnostic analysis
US5128015A (en) * 1988-03-15 1992-07-07 Tall Oak Ventures Method and apparatus for amperometric diagnostic analysis
US5120420B1 (en) * 1988-03-31 1999-11-09 Matsushita Electric Ind Co Ltd Biosensor and a process for preparation thereof
US5120420A (en) * 1988-03-31 1992-06-09 Matsushita Electric Industrial Co., Ltd. Biosensor and a process for preparation thereof
US5272087A (en) * 1988-04-20 1993-12-21 Centre National De La Recherche Scientifique (C.N.R.S.) Enzymatic electrode and its preparation method
US5126034A (en) * 1988-07-21 1992-06-30 Medisense, Inc. Bioelectrochemical electrodes
US5312590A (en) * 1989-04-24 1994-05-17 National University Of Singapore Amperometric sensor for single and multicomponent analysis
US5314605A (en) * 1989-06-30 1994-05-24 Dragerwerk Aktiengesellschaft Measuring cell for electrochemically detecting a gas
US4988429A (en) * 1989-06-30 1991-01-29 Dragerwerk Aktiengesellschaft Measuring cell for an electrochemical gas sensor
US5229282A (en) * 1989-11-24 1993-07-20 Matsushita Electric Industrial Co., Ltd. Preparation of biosensor having a layer containing an enzyme, electron acceptor and hydrophilic polymer on an electrode system
US5508171A (en) * 1989-12-15 1996-04-16 Boehringer Mannheim Corporation Assay method with enzyme electrode system
US5122244A (en) * 1990-02-03 1992-06-16 Boehringer Mannheim Gmbh Method and sensor electrode system for the electrochemical determination of an analyte or an oxidoreductase as well as the use of suitable compounds therefor
US5059908A (en) * 1990-05-31 1991-10-22 Capital Controls Company, Inc. Amperimetric measurement with cell electrode deplating
US5266179A (en) * 1990-07-20 1993-11-30 Matsushita Electric Industrial Co., Ltd. Quantitative analysis method and its system using a disposable sensor
US5320732A (en) * 1990-07-20 1994-06-14 Matsushita Electric Industrial Co., Ltd. Biosensor and measuring apparatus using the same
US5192415A (en) * 1991-03-04 1993-03-09 Matsushita Electric Industrial Co., Ltd. Biosensor utilizing enzyme and a method for producing the same
US5382346A (en) * 1991-05-17 1995-01-17 Kyoto Daiichi Kagaku Co., Ltd. Biosensor and method of quantitative analysis using the same
US5264103A (en) * 1991-10-18 1993-11-23 Matsushita Electric Industrial Co., Ltd. Biosensor and a method for measuring a concentration of a substrate in a sample
US5512159A (en) * 1992-01-21 1996-04-30 Matsushita Electric Industrial Co. Ltd. Biosensor
US5384028A (en) * 1992-08-28 1995-01-24 Nec Corporation Biosensor with a data memory
US5393399A (en) * 1992-09-07 1995-02-28 Gie Cylergie Amperometric measuring device having an electrochemical sensor
US5385846A (en) * 1993-06-03 1995-01-31 Boehringer Mannheim Corporation Biosensor and method for hematocrit determination
US5405511A (en) * 1993-06-08 1995-04-11 Boehringer Mannheim Corporation Biosensing meter with ambient temperature estimation method and system
US5413690A (en) * 1993-07-23 1995-05-09 Boehringer Mannheim Corporation Potentiometric biosensor and the method of its use
US5502396A (en) * 1993-09-21 1996-03-26 Asulab S.A. Measuring device with connection for a removable sensor
US5645709A (en) * 1993-12-08 1997-07-08 Van Den Bergh Foods Co., Division Of Conopco, Inc. Methods and apparatus for electrochemical measurements
US5520787A (en) * 1994-02-09 1996-05-28 Abbott Laboratories Diagnostic flow cell device
US5437999A (en) * 1994-02-22 1995-08-01 Boehringer Mannheim Corporation Electrochemical sensor
US5846422A (en) * 1994-03-04 1998-12-08 Memtec America Corporation Large pore synthetic polymer membranes
US5518590A (en) * 1994-06-21 1996-05-21 Pennzoil Products Company Electrochemical sensors for motor oils and other lubricants
US5607565A (en) * 1995-03-27 1997-03-04 Coulter Corporation Apparatus for measuring analytes in a fluid sample
US5527446A (en) * 1995-04-13 1996-06-18 United States Of America As Represented By The Secretary Of The Air Force Gas sensor
US5620579A (en) * 1995-05-05 1997-04-15 Bayer Corporation Apparatus for reduction of bias in amperometric sensors
US5567302A (en) * 1995-06-07 1996-10-22 Molecular Devices Corporation Electrochemical system for rapid detection of biochemical agents that catalyze a redox potential change
US5628890A (en) * 1995-09-27 1997-05-13 Medisense, Inc. Electrochemical sensor
US5942102A (en) * 1995-11-16 1999-08-24 Usf Filtration And Separations Group Inc. Electrochemical method
US6270637B1 (en) * 1997-12-05 2001-08-07 Roche Diagnostics Corporation Electrochemical biosensor test strip
US5997817A (en) * 1997-12-05 1999-12-07 Roche Diagnostics Corporation Electrochemical biosensor test strip

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8071384B2 (en) 1997-12-22 2011-12-06 Roche Diagnostics Operations, Inc. Control and calibration solutions and methods for their use
US8586373B2 (en) 2003-06-20 2013-11-19 Roche Diagnostics Operations, Inc. System and method for determining the concentration of an analyte in a sample fluid
US7645421B2 (en) 2003-06-20 2010-01-12 Roche Diagnostics Operations, Inc. System and method for coding information on a biosensor test strip
US7718439B2 (en) 2003-06-20 2010-05-18 Roche Diagnostics Operations, Inc. System and method for coding information on a biosensor test strip
US8058077B2 (en) 2003-06-20 2011-11-15 Roche Diagnostics Operations, Inc. Method for coding information on a biosensor test strip
US7645373B2 (en) 2003-06-20 2010-01-12 Roche Diagnostic Operations, Inc. System and method for coding information on a biosensor test strip
US8083993B2 (en) 2003-06-20 2011-12-27 Riche Diagnostics Operations, Inc. System and method for coding information on a biosensor test strip
US8663442B2 (en) 2003-06-20 2014-03-04 Roche Diagnostics Operations, Inc. System and method for analyte measurement using dose sufficiency electrodes
US8148164B2 (en) 2003-06-20 2012-04-03 Roche Diagnostics Operations, Inc. System and method for determining the concentration of an analyte in a sample fluid
US8206565B2 (en) 2003-06-20 2012-06-26 Roche Diagnostics Operation, Inc. System and method for coding information on a biosensor test strip
US8293538B2 (en) 2003-06-20 2012-10-23 Roche Diagnostics Operations, Inc. System and method for coding information on a biosensor test strip
US8298828B2 (en) 2003-06-20 2012-10-30 Roche Diagnostics Operations, Inc. System and method for determining the concentration of an analyte in a sample fluid
US8507289B1 (en) 2003-06-20 2013-08-13 Roche Diagnostics Operations, Inc. System and method for coding information on a biosensor test strip
US9410915B2 (en) 2004-06-18 2016-08-09 Roche Operations Ltd. System and method for quality assurance of a biosensor test strip
US8092668B2 (en) 2004-06-18 2012-01-10 Roche Diagnostics Operations, Inc. System and method for quality assurance of a biosensor test strip
US20070246357A1 (en) * 2004-10-12 2007-10-25 Huan-Ping Wu Concentration Determination in a Diffusion Barrier Layer
US8852422B2 (en) 2004-10-12 2014-10-07 Bayer Healthcare Llc Concentration determination in a diffusion barrier layer
US9206460B2 (en) 2004-10-12 2015-12-08 Bayer Healthcare Llc Concentration determination in a diffusion barrier layer
US8317988B2 (en) 2004-10-12 2012-11-27 Bayer Healthcare Llc Concentration determination in a diffusion barrier layer
US9546974B2 (en) 2004-10-12 2017-01-17 Ascensia Diabetes Care Holdings Ag Concentration determination in a diffusion barrier layer

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