WO2006027703A2

WO2006027703A2 - Analyte detecting member with a hydrogel

Info

Publication number: WO2006027703A2
Application number: PCT/IB2005/003787
Authority: WO
Inventors: Norbert Bartetzko; Bernfried Specht; Robert Bartetzko
Original assignee: Albatros Technologies Gmbh & Co. Kg
Priority date: 2004-09-09
Filing date: 2005-09-09
Publication date: 2006-03-16
Also published as: WO2006027703A3; WO2006027703A9

Abstract

Methods and apparatus are provided for an analyte detecting device. In one embodiment, the apparatus comprises a substrate; a plurality of conductive lines on said substrate; an insulating layer on said substrate; at least one working electrode and at least one counter electrode, each coupled to at least one conductive line; a cover film; and a support layer; a PSA layer, wherein the detecting member is masked to reduce the volume used for the detecting member. The device may be a hydrogel based analyte detecting member for use in spot monitoring glucose levels in blood.

Description

ANALYTE DETECTING MEMBER WITH A HYDROGEL

BACKGROUND OF THE INVENTION

Technical Field:

The technical field relates to analyte detecting devices, and more specifically, to sample capture and use of a hydrogel for analyte detecting devices. Background Art: Test strips are known in the medical health-care products industry for analyzing analyte levels such as but not limited to, glucose levels in blood. For this type of analysis, a drop of blood is typically obtained by making a small incision in the fingertip, creating a small wound, which generates a small blood droplet on the surface of the skin. A test strip is brought by the user to the blood droplet at the wound and engaged in a manner to bring blood to an analysis site on the test strip. The test strip is then coupled to a metering device which typically uses an electrochemical technique to determine the amount of glucose in the blood.

Early methods of using test strips required a relatively substantial volume of blood to obtain an accurate glucose measurement. This large blood requirement made the monitoring experience a painful one for the user since the user may need to lance deeper than comfortable to obtain sufficient blood generation. Alternatively, if insufficient blood is spontaneously generated, the user may need to "milk" the wound to squeeze enough blood to the skin surface. Neither method is desirable as they take additional user effort and may be painful. The discomfort and inconvenience associated with such lancing events may deter a user from testing their blood glucose levels in a rigorous manner sufficient to control their diabetes. A further impediment to patient compliance is the amount of time that it takes for a glucose measurement to be completed. Known devices can take a substantial amount of time to arrive at a glucose level. The more time it takes to arrive at a measurement, the less the likely that the user will stay with their testing regime. A further impediment to patient compliance is the amount of time that at lower volumes, it becomes even more important that blood or other fluid sample be directed to a measurement device without being wasted or spilled along the way. Known devices do not effectively handle the low sample volumes in an efficient manner. Accordingly, improved sensing devices are desired to increase user compliance and reduce the hurdles associated with analyte measurement. SUMMARY OF THE INVENTION

The present invention provides solutions for at least some of the drawbacks discussed above. Specifically, some embodiments of the present invention provide an improved apparatus for measuring analyte levels in a body fluid. The present invention also provided improved techniques for sample capture used with such analyte detecting devices. For example, in some embodiments of the present invention, a hydro gel layer may be used to stabilize materials in the analyte detecting member that allow of low volume measurement techniques. At least some of these and other objectives described herein will be met by embodiments of the present invention. hi one embodiment of the present invention, it should be understood that the variable amount of blood yield on lancing for shallow depth is between 0.2 and 0.5 μL. To optimize sample acquisition probability for samples of the order of 0.2 μL it would be useful to have a very low sensor volume, of the order of 0.1 μL. In one embodiment of the present invention, masking the 0.4 μL standard analyte detecting device used by applicant and lowering the height of the cover can achieve 40 nL sample volume requirements without much optimization.

In one embodiment, the apparatus comprises a substrate, a plurality of conductive lines on the substrate, an insulating layer on the substrate, at least one working electrode, and at least one counter electrode, each coupled to at least one conductive line. The apparatus may also include a cover film, a support layer, and a PSA layer, wherein the detecting member is masked to reduce the volume of sample fluid used for the detecting member. In one embodiment, the masking reduces the volume to 40 nanoliter. It should be understood that other embodiments may be masked so that the volume used is no more than 100, 90, 80, 70, 60, 50, 40, 30, 20, 10, or fewer nanoliters. Some embodiments may be masked so that volume that can be held in the sample chamber does not exceed 100, 90, 80, 70, 60, 50, 40, 30, 20, 10, or more nanoliters. In another embodiment, the present invention provides a method of manufacturing an analyte detecting device. The method comprises providing a substrate, applying a plurality of layers of materials on the substrate, wherein the layers form an electrode device; and printing a hydrogel on the layers forming an electrode device, wherein the hydrogel is with a mediator.

In yet another embodiment, the present invention provides a method of manufacturing an analyte detecting device. The method comprises providing a substrate; applying a plurality of layers of materials on the substrate, wherein the layers form an electrode device; and printing a hydrogel on the layers forming an electrode device, wherein the hydrogel is without an enzyme. In one embodiment, the present invention provides a method of manufacturing an analyte detecting device. The method comprising providing a substrate; applying a plurality of layers of materials on the substrate, wherein the layers form an electrode device; and printing a hydrogel on the layers forming an electrode device, wherein the hydrogel is without glucose oxidase. In one embodiment, the present invention provides a method of manufacturing an analyte detecting device. The method comprises providing a substrate; applying a plurality of layers of materials on the substrate, wherein the layers form an electrode device; and printing a hydrogel containing a zwitterionic material on the layers forming an electrode device, wherein the electrode device comprises a non-platinum working electrode. hi one embodiment, the present invention provides a method of manufacturing an analyte detecting device. The method comprises providing a substrate; applying a plurality of layers of materials on the substrate, wherein the layers form an electrode device; and printing a hydrogel containing CHAPS or its derivatives on the layers forming an electrode device, wherein the electrode device comprises a non-platinum working electrode. In one embodiment, the present invention provides a method of manufacturing an analyte detecting device. The method comprises providing a substrate; applying a plurality of layers of materials on the substrate; and printing a hydrogel on a layer of carbon paste, wherein the carbon paste contains a mediator and the hydrogel stabilizes the mediator in the carbon paste.

In one embodiment, the present invention provides a method of manufacturing an analyte detecting device. The method comprises providing a substrate; applying a plurality of layers of materials on the substrate; and printing a hydrogel on a layer of carbon paste, wherein the carbon paste contains a mediator and an enzyme.

In one embodiment, the present invention provides a method of manufacturing an analyte detecting device. The method comprises providing a substrate; applying a plurality of layers of materials on the substrate; and printing a hydrogel on a layer of carbon paste, wherein the carbon paste contains a mediator and an enzyme; wherein the hydrogel concentrates the mediator near a top layer of the carbon paste.

In one embodiment, the present invention provides a method of manufacturing an analyte detecting device. The method comprises providing a substrate; applying a plurality of layers of materials on the substrate; and printing a hydrogel on top of one of the layers, wherein the layer contains a mediator and an enzyme.

In one embodiment, the present invention provides a method of manufacturing an analyte detecting device. The method comprises providing a substrate; applying a plurality of layers of materials on the substrate; and printing a hydro gel on one of the layers, wherein the hydro gel contains a high molecular weight cross-linker (macromer) with a Mn greater than about 700 g/mol.

In one embodiment, the present invention provides a device comprising: a substrate; a plurality of layers of materials on the substrate; and a hydro gel on one of the layers, wherein the hydrogel is hydrophilic and is configured to stabilize a mediator in a layer immediately below the hydrogel.

In one embodiment, the present invention provides a method of manufacturing an analyte detecting device. The method comprises providing a substrate; applying a plurality of layers of materials on the substrate; and printing a hydrogel on one of the layers, wherein the hydrogel comprises PVP, CHAPS, Trinton X-100, a retarder, and an antifoam. In other embodiments, the hydrogel contains at least one of PVP, CHAPS, Trinton X-100, a retarder, and an antifoam. hi another embodiment, the hydrogel contains at least two materials selected from the following: PVP, CHAPS, Trinton X-100, a retarder, and an antifoam. hi yet another embodiment, the hydrogel contains at least three materials selected from the following: PVP, CHAPS, Trinton X- 100, a retarder, and an antifoam. hi yet another embodiment, the hydrogel contains at least four materials selected from the following: PVP, CHAPS, Trinton X-100, a retarder, and an antifoam.

In one embodiment, the present invention provides a method of manufacturing an analyte detecting device. The method comprises providing a substrate; applying a plurality of layers of materials on the substrate; and printing only one layer of hydrogel on top of the electrode material.

In one embodiment, the present invention provides a method of manufacturing an analyte detecting device. The method comprises providing a substrate; applying a plurality of layers of materials on the substrate; printing a hydrogel on one of the layers; and applying a layer containing at least one mediator, the hydrogel being formed in contact with the one mediator; wherein the hydrogel layer is formed directly over the working electrode. hi one embodiment, the present invention provides a method of manufacturing an analyte detecting device. The method comprises providing a substrate; applying a plurality of layers of materials on the substrate; printing a hydrogel on one of the layers; and applying a layer containing at least one mediator, the hydrogel being formed in contact with the one mediator. In one embodiment, the method of manufacturing may be used without forming a cellulose acetate membrane. The method wherein the hydrogel layer is formed directly over the working electrode.

In one embodiment, the present invention provides a compound for use on an analyte detecting device. The compound comprising a cross-linkable hydrophilic polymer dispersion containing a hydrophilic monomer mixture, a low molecular weight cross-linker and a hydrophilic high molecular weight polymer with an initiator.

In some embodiments, the compound may be configured to allow rapid wicking of the analyte solution as well as rapid swelling of the resulting hydrogel membrane to allow a fast diffusion of the analyte to the enzyme. In other embodiments, the compound maybe configured to achieve highly cross-linked hydrogel to allow the permeation of low molecular weight analytes to the entrapped enzyme.

Additionally, it should be understood that embodiments of the present invention may comprise of an analyte detecting member that has a hydrogel layer that does not contain GOD. Such a device may or may not have an outer membrane layer. It should be understood that the present invention may provide analyte detecting members with mediators in the carbon paste. The present invention may include a sample chamber/capillary for sample capture and is not limited to a "topfill" geometry. The present invention may use high molecular weight cross- linkers (macromers) greater than a Mn = 700 g/mol.

The present invention may comprise of an analyte detecting member using a electrode made of a non-platinum material with a hydrogel layer above the electrode for use in glucose measurement. The non-platinum material includes, but is not limited to, carbon paste. It should be understood that some embodiments only use one layer of hydrogel over the electrode. Although not limited to the following, the hydrogel may be a non-3D hydrogel.

It should be understood that some embodiments of the present invention may have a hydrogel layer that contain pores. In one embodiment, the pores in the hydrogel are greater than 2 microns in diameter. In another embodiment, the pores are at least 2.25 microns in diameter. In a still further embodiment, the pores are at least 2.5 microns in diameter. It should be understood that other embodiments may have pore sizes such as, but not limited to, 2.75, 3, 3.25, 3.5, 4, and other diameters. A further understanding of the nature and advantages of the invention will become apparent by reference to the remaining portions of the specification and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 illustrates an embodiment of a controllable force driver in the form of a cylindrical electric penetrating member driver using a coiled solenoid -type configuration.

Figure 2A illustrates a displacement over time profile of a penetrating member driven by a harmonic spring/mass system.

Figure 2B illustrates the velocity over time profile of a penetrating member driver by a harmonic spring/mass system.

Figure 2C illustrates a displacement over time profile of an embodiment of a controllable force driver. Figure 2D illustrates a velocity over time profile of an embodiment of a controllable force driver.

Figure 3 is a diagrammatic view illustrating a controlled feed-back loop. Figure 4 is a perspective view of a tissue penetration device having features of the invention. Figure 5 is an elevation view in partial longitudinal section of the tissue penetration device of Figure 4.

Figure 6 shows an exploded perspective view of one embodiment of a device according to the present invention.

Figure 7 is a top-down view of one embodiment of the present invention. Figures 8 A -8C show other top-down views of embodiments of the present invention.

Figures 9 A and 9B show exploded perspective views of embodiments of the present invention.

Figures 1OA through 1OC show cross-sectional views of sample capture devices. Figure 11 shows a cross-sectional view of a sample capture device. Figures 12 through 15 show cross-sectional views of various layers of the present invention.

Figures 16 through 18 show perspective views of embodiment of the present invention. Figures 19 and 20 show top down views of embodiments of the present invention.

DESCRIPTION OF THE SPECIFIC EMBODIMENTS

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed. It may be noted that, as used in the specification and the appended claims, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a material" may include mixtures of materials, reference to "a chamber" may include multiple chambers, and the like. References cited herein are hereby incorporated by reference in their entirety, except to the extent that they conflict with teachings explicitly set forth in this specification.

In this specification and in the claims which follow, reference will be made to a number of terms which shall be defined to have the following meanings:

"Optional" or "optionally" means that the subsequently described circumstance may or may not occur, so that the description includes instances where the circumstance occurs and instances where it does not. For example, if a device optionally contains a feature for analyzing a blood sample, this means that the analysis feature may or may not be present, and, thus, the description includes structures wherein a device possesses the analysis feature and structures wherein the analysis feature is not present.

The present invention may be used with a variety of different penetrating member drivers. It is contemplated that these penetrating member drivers may be spring based, solenoid based, magnetic driver based, nanomuscle based, or based on any other mechanism useful in moving a penetrating member along a path into tissue. It should be noted that the present invention is not limited by the type of driver used with the penetrating member feed mechanism. One suitable penetrating member driver for use with the present invention is shown in Figure 1. This is an embodiment of a solenoid type electromagnetic driver that is capable of driving an iron core or slug mounted to the penetrating member assembly using a direct current (DC) power supply. The electromagnetic driver includes a driver coil pack that is divided into three separate coils along the path of the penetrating member, two end coils and a middle coil. Direct current is alternated to the coils to advance and retract the penetrating member. Although the driver coil pack is shown with three coils, any suitable number of coils may be used, for example, 4, 5, 6, 7 or more coils may be used.

Referring to the embodiment of Figure 1, the stationary iron housing 10 may contain the driver coil pack with a first coil 12 flanked by iron spacers 14 which concentrate the magnetic flux at the inner diameter creating magnetic poles. The inner insulating housing 16 isolates the penetrating member 18 and iron core 20 from the coils and provides a smooth, low friction guide surface. The penetrating member guide 22 further centers the penetrating member 18 and iron core 20. The penetrating member 18 is protracted and retracted by alternating the current between the first coil 12, the middle coil, and the third coil to attract the iron core 20. Reversing the coil sequence and attracting the core and penetrating member back into the housing retracts the penetrating member. The penetrating member guide 22 also serves as a stop for the iron core 20 mounted to the penetrating member 18.

As discussed above, tissue penetration devices which employ spring or cam driving methods have a symmetrical or nearly symmetrical actuation displacement and velocity profiles on the advancement and retraction of the penetrating member as shown in Figures 2 and 3. In most of the available lancet devices, once the launch is initiated, the stored energy determines the velocity profile until the energy is dissipated. Controlling impact, retraction velocity, and dwell time of the penetrating member within the tissue can be useful in order to achieve a high success rate while accommodating variations in skin properties and minimize pain. Advantages can be achieved by taking into account of the fact that tissue dwell time is related to the amount of skin deformation as the penetrating member tries to puncture the surface of the skin and variance in skin deformation from patient to patient based on skin hydration.

In this embodiment, the ability to control velocity and depth of penetration may be achieved by use of a controllable force driver where feedback is an integral part of driver control. Such drivers can control either metal or polymeric penetrating members or any other type of tissue penetration element. The dynamic control of such a driver is illustrated in Figure. 2C which illustrates an embodiment of a controlled displacement profile and Figure 2D which illustrates an embodiment of a the controlled velocity profile. These are compared to Figures 2A and 2B, which illustrate embodiments of displacement and velocity profiles, respectively, of a harmonic spring/mass powered driver. Reduced pain can be achieved by using impact velocities of greater than about 2 m/s entry of a tissue penetrating element, such as a lancet, into tissue. Other suitable embodiments of the penetrating member driver are described in commonly assigned, copending U.S. Patent Application Ser. No. 10/127,395, (Attorney Docket No. 38187-2551) filed April 19, 2002 and previously incorporated herein.

Figure 3 illustrates the operation of a feedback loop using a processor 60. The processor 60 stores profiles 62 in non- volatile memory. A user inputs information 64 about the desired circumstances or parameters for a lancing event. The processor 60 selects a driver profile 62 from a set of alternative driver profiles that have been preprogrammed in the processor 60 based on typical or desired tissue penetration device performance determined through testing at the factory or as programmed in by the operator. The processor 60 may customize by either scaling or modifying the profile based on additional user input information 64. Once the processor has chosen and customized the profile, the processor 60 is ready to modulate the power from the power supply 66 to the penetrating member driver 68 through an amplifier 70. The processor 60 may measure the location of the penetrating member 72 using a position sensing mechanism 74 through an analog to digital converter 76 linear encoder or other such transducer. Examples of position sensing mechanisms have been described in the embodiments above and may be found in the specification for commonly assigned, copending U.S. Patent Application Ser. No. 10/127,395, (Attorney Docket No. 38187-2551) filed April 19, 2002 and previously incorporated herein. The processor 60 calculates the movement of the penetrating member by comparing the actual profile of the penetrating member to the predetermined profile. The processor 60 modulates the power to the penetrating member driver 68 through a signal generator 78, which may control the amplifier 70 so that the actual velocity profile of the penetrating member does not exceed the predetermined profile by more than a preset error limit. - The error limit is the accuracy in the control of the penetrating member.

After the lancing event, the processor 60 can allow the user to rank the results of the lancing event. The processor 60 stores these results and constructs a database 80 for the individual user. Using the database 79, the processor 60 calculates the profile traits such as degree of painlessness, success rate, and blood volume for various profiles 62 depending on user input information 64 to optimize the profile to the individual user for subsequent lancing cycles. These profile traits depend on the characteristic phases of penetrating member advancement and retraction. The processor 60 uses these calculations to optimize profiles 62 for each user. In addition to user input information 64, an internal clock allows storage in the database 79 of information such as the time of day to generate a time stamp for the lancing event and the time between lancing events to anticipate the user's diurnal needs. The database stores information and statistics for each user and each profile that particular user uses.

In addition to varying the profiles, the processor 60 can be used to calculate the appropriate penetrating member diameter and geometry suitable to realize the blood volume required by the user. For example, if the user requires about 1-5 microliter volume of blood, the processor 60 may select a 200 micron diameter penetrating member to achieve these results. For each class of penetrating member, both diameter and penetrating member tip geometry, is stored in the processor 60 to correspond with upper and lower limits of attainable blood volume based on the predetermined displacement and velocity profiles.

The lancing device is capable of prompting the user for information at the beginning and the end of the lancing event to more adequately suit the user. The goal is to either change to a different profile or modify an existing profile. Once the profile is set, the force driving the penetrating member is varied during advancement and retraction to follow the profile. The method of lancing using the lancing device comprises selecting a profile, lancing according to the selected profile, determining lancing profile traits for each characteristic phase of the lancing cycle, and optimizing profile traits for subsequent lancing events. Figure 4 illustrates an embodiment of a tissue penetration device, more specifically, a lancing device 80 that includes a controllable driver 179 coupled to a tissue penetration element. The lancing device 80 has a proximal end 81 and a distal end 82. At the distal end 82 is the tissue penetration element in the form of a penetrating member 83, which is coupled to an elongate coupler shaft 84 by a drive coupler 85. The elongate coupler shaft 84 has a proximal end 86 and a distal end 87. A driver coil pack 88 is disposed about the elongate coupler shaft 84 proximal of the penetrating member 83. A position sensor 91 is disposed about a proximal portion 92 of the elongate coupler shaft 84 and an electrical conductor 94 electrically couples a processor 93 to the position sensor 91. The elongate coupler shaft 84 driven by the driver coil pack 88 controlled by the position sensor 91 and processor 93 form the controllable driver, specifically, a controllable electromagnetic driver.

Referring to Figure 5, the lancing device 80 can be seen in more detail, in partial longitudinal section. The penetrating member 83 has a proximal end 95 and a distal end 96 with a sharpened point at the distal end 96 of the penetrating member 83 and a drive head 98 disposed at the proximal end 95 of the penetrating member 83. A penetrating member shaft 201 is disposed between the drive head 98 and the sharpened point 97. The penetrating member shaft 201 may be comprised of stainless steel, or any other suitable material or alloy and have a transverse dimension of about 0.1 to about 0.4 mm. The penetrating member shaft may have a length of about 3 mm to about 50 mm, specifically, about 15 mm to about 20 mm. The drive head 98 of the penetrating member 83 is an enlarged portion having a transverse dimension greater than a transverse dimension of the penetrating member shaft 201 distal of the drive head 98. This configuration allows the drive head 98 to be mechanically captured by the drive coupler 85. The drive head 98 may have a transverse dimension of about 0.5 to about 2 mm.

A magnetic member 102 is secured to the elongate coupler shaft 84 proximal of the drive coupler 85 on a distal portion 203 of the elongate coupler shaft 84. The magnetic member 102 is a substantially cylindrical piece of magnetic material having an axial lumen 204 extending the length of the magnetic member 102. The magnetic member 102 has an outer transverse dimension that allows the magnetic member 102 to slide easily within an axial lumen 105 of a low friction, possibly lubricious, polymer guide tube 105' disposed within the driver coil pack 88. The magnetic member 102 may have an outer transverse dimension of about 1.0 to about 5.0 mm, specifically, about 2.3 to about 2.5 mm. The magnetic member 102 may have a length of about 3.0 to about 5.0 mm, specifically, about 4.7 to about 4.9 mm. The magnetic member 102 can be made from a variety of magnetic materials including ferrous metals such as ferrous steel, iron, ferrite, or the like. The magnetic member 102 may be secured to the distal portion 203 of the elongate coupler shaft 84 by a variety of methods including adhesive or epoxy bonding, welding, crimping or any other suitable method.

Proximal of the magnetic member 102, an optical encoder flag 206 is secured to the elongate coupler shaft 84. The optical encoder flag 206 is configured to move within a slot 107 in the position sensor 91. The slot 107 of the position sensor 91 is formed between a first body portion 108 and a second body portion 109 of the position sensor 91. The slot 107 may have separation width of about 1.5 to about 2.0 mm. The optical encoder flag 206 can have a length of about 14 to about 18 mm, a width of about 3 to about 5 mm and a thickness of about 0.04 to about 0.06 mm. The optical encoder flag 206 interacts with various optical beams generated by LEDs disposed on or in the position sensor body portions 108 and 109 in a predetermined manner. The interaction of the optical beams generated by the LEDs of the position sensor 91 generates a signal that indicates the longitudinal position of the optical flag 206 relative to the position sensor 91 with a substantially high degree of resolution. The resolution of the position sensor 91 may be about 200 to about 400 cycles per inch, specifically, about 350 to about 370 cycles per inch. The position sensor 91 may have a speed response time (position/time resolution) of 0 to about 120,000 Hz, where one dark and light stripe of the flag constitutes one Hertz, or cycle per second. The position of the optical encoder flag 206 relative to the magnetic member 102, driver coil pack 88 and position sensor 91 is such that the optical encoder 91 can provide precise positional information about the penetrating member 83 over the entire length of the penetrating member's power stroke.

An optical encoder that is suitable for the position sensor 91 is a linear optical incremental encoder, model HEDS 9200, manufactured by Agilent Technologies. The model HEDS 9200 may have a length of about 20 to about 30 mm, a width of about 8 to about 12 mm, and a height of about 9 to about 11 mm. Although the position sensor 91 illustrated is a linear optical incremental encoder, other suitable position sensor embodiments could be used, provided they posses the requisite positional resolution and time response. The HEDS 9200 is a two channel device where the channels are 90 degrees out of phase with each other. This results in a resolution of four times the basic cycle of the flag. These quadrature outputs make it possible for the processor to determine the direction of penetrating member travel. Other suitable position sensors include capacitive encoders, analog reflective sensors, such as the reflective position sensor discussed above, and the like. A coupler shaft guide 111 is disposed towards the proximal end 81 of the lancing device

80. The guide 111 has a guide lumen 112 disposed in the guide 111 to slidingly accept the proximal portion 92 of the elongate coupler shaft 84. The guide 111 keeps the elongate coupler shaft 84 centered horizontally and vertically in the slot 102 of the optical encoder 91.

Referring now to Figure 6, a still further embodiment of a cartridge according to the present invention will be described. Figure 6 shows one embodiment of a cartridge 300 which may be removably inserted into an apparatus for driving penetrating members to pierce skin or • tissue. The cartridge 300 has a plurality of penetrating members 302 that may be individually or otherwise selectively actuated so that the penetrating members 302 may extend outward from the cartridge, as indicated by arrow 304, to penetrate tissue. In the present embodiment, the cartridge 300 may be based on a flat disc with a number of penetrating members such as, but in no way limited to, (25, 50, 75, 100, ...) arranged radially on the disc or cartridge 800. It should be understood that although the cartridge 300 is shown as a disc or a disc-shaped housing, other shapes or configurations of the cartridge may also work without departing from the spirit of the present invention of placing a plurality of penetrating members to be engaged, singly or in some combination, by a penetrating member driver.

Each penetrating member 302 may be contained in a cavity 306 in the cartridge 300 with the penetrating member's sharpened end facing radially outward and may be in the same plane as that of the cartridge. The cavity 306 may be molded, pressed, forged, or otherwise formed in the cartridge. Although not limited in this manner, the ends of the cavities 306 may be divided into individual fingers (such as one for each cavity) on the outer periphery of the disc. The particular shape of each cavity 306 may be designed to suit the size or shape of the penetrating member therein or the amount of space desired for placement of the analyte detecting members 808. For example and not limitation, the cavity 306 may have a V-shaped cross-section, a U- shaped cross-section, C-shaped cross-section, a multi-level cross section or the other cross- sections. The opening 810 through which a penetrating member 302 may exit to penetrate tissue may also have a variety of shapes, such as but not limited to, a circular opening, a square or rectangular opening, a U-shaped opening, a narrow opening that only allows the penetrating member to pass, an opening with more clearance on the sides, a slit, a configuration as shown in Figure 75, or the other shapes.

In this embodiment, after actuation, the penetrating member 302 is returned into the cartridge and may be held within the cartridge 300 in a manner so that it is not able to be used again. By way of example and not limitation, a used penetrating member may be returned into the cartridge and held by the launcher in position until the next lancing event. At the time of the next lancing, the launcher may disengage the used penetrating member with the cartridge 300 turned or indexed to the next clean penetrating member such that the cavity holding the used penetrating member is position so that it is not accessible to the user (i.e. turn away from a penetrating member exit opening), hi some embodiments, the tip of a used penetrating member may be driven into a protective stop that hold the penetrating member in place after use. The cartridge 300 is replaceable with a new cartridge 300 once all the penetrating members have been used or at such other time or condition as deemed desirable by the user.

Referring still to the embodiment in Figure 6, the cartridge 300 may provide sterile environments for penetrating members via seals, foils, covers, polymeric, or similar materials used to seal the cavities and provide enclosed areas for the penetrating members to rest in. hi the present embodiment, a foil or seal layer 320 is applied to one surface of the cartridge 300. The seal layer 320 may be made of a variety of materials such as a metallic foil or other seal materials and may be of a tensile strength and other quality that may provide a sealed, sterile environment until the seal layer 320 is penetrate by a suitable or penetrating device providing a preselected or selected amount of force to open the sealed, sterile environment. Each cavity 306 may be individually sealed with a layer 320 in a manner such that the opening of one cavity does not interfere with the sterility in an adjacent or other cavity in the cartridge 800. As seen in the embodiment of Figure 6, the seal layer 320 may be a planar material that is adhered to a top surface of the cartridge 800.

Depending on the orientation of the cartridge 300 in the penetrating member driver apparatus, the seal layer 320 may be on the top surface, side surface, bottom surface, or other positioned surface. For ease of illustration and discussion of the embodiment of Figure 6, the layer 320 is placed on a top surface of the cartridge 800. The cavities 306 holding the penetrating members 302 are sealed on by the foil layer 320 and thus create the sterile environments for the penetrating members. The foil layer 320 may seal a plurality of cavities 306 or only a select number of cavities as desired. In a still further feature of Figure 6, the cartridge 300 may optionally include a plurality of analyte detecting members 308 on a substrate 822 which may be attached to a bottom surface of the cartridge 300. The substrate may be made of a material such as, but not limited to, a polymer, a foil, or other material suitable for attaching to a cartridge and holding the analyte detecting members 308. As seen in Figure 6, the substrate 322 may hold a plurality of analyte detecting members, such as but not limited to, about 10-50, 50-100, or other combinations of analyte detecting members. This facilitates the assembly and integration of analyte detecting members 308 with cartridge 300. These analyte detecting members 308 may enable an integrated body fluid sampling system where the penetrating members 302 create a wound tract in a target tissue, which expresses body fluid that flows into the cartridge for analyte detection by at least one of the analyte detecting members 308. The substrate 322 may contain any number of analyte detecting members 308 suitable for detecting analytes in cartridge having a plurality of cavities 306. hi one embodiment, many analyte detecting members 308 may be printed onto a single substrate 322 which is then adhered to the cartridge to_. facilitate manufacturing and simplify assembly. The analyte detecting members 308 may be electrochemical in nature. The analyte detecting members 308 may further contain enzymes, dyes, or other detectors which react when exposed to the desired analyte. Additionally, the analyte detecting members 308 may comprise of clear optical windows that allow light to pass into the body fluid for analyte analysis. The number, location, and type of analyte detecting member 308 may be varied as desired, based in part on the design of the cartridge, number of analytes to be measured, the need for analyte detecting member calibration, and the sensitivity of the analyte detecting members. If the cartridge 300 uses an analyte detecting member arrangement where the analyte detecting members are on a substrate attached to the bottom of the cartridge, there may be through holes (as shown in Figure 76), wicking elements, capillary tube or other devices on the cartridge 300 to allow body fluid to flow from the cartridge to the analyte detecting members 308 for analysis. Li other configurations, the analyte detecting members 308 may be printed, formed, or otherwise located directly in the cavities housing the penetrating members 302 or areas on the cartridge surface that receive blood after lancing.

The use of the seal layer 320 and substrate or analyte detecting member layer 822 may facilitate the manufacture of these cartridges 10. For example, a single seal layer 320 may be adhered, attached, or otherwise coupled to the cartridge 300 as indicated by arrows 324 to seal many of the cavities 306 at one time. A sheet 322 of analyte detecting members may also be adhered, attached, or otherwise coupled to the cartridge 300 as indicated by arrows 325 to provide many analyte detecting members on the cartridge at one time. During manufacturing of one embodiment of the present invention, the cartridge 300 may be loaded with penetrating members 302, sealed with layer 320 and a temporary layer (not shown) on the bottom where substrate 322 would later go, to provide a sealed environment for the penetrating members. This assembly with the temporary bottom layer is then taken to be sterilized. After sterilization, the assembly is taken to a clean room (or it may already be in a clear room or equivalent environment) where the temporary bottom layer is removed and the substrate 322 with analyte detecting members is coupled to the cartridge as shown in Figure 6. This process allows for the sterile assembly of the cartridge with the penetrating members 302 using processes and/or temperatures that may degrade the accuracy or functionality of the analyte detecting members on substrate 322. As a nonlimiting example, the entire cartridge 300 may then be placed in a further sealed container such as a pouch, bag, plastic molded container, etc...to facilitate contact, improve ruggedness, and/or allow for easier handling.

In some embodiments, more than one seal layer 320 may be used to seal the cavities 306. As examples of some embodiments, multiple layers may be placed over each cavity 306, half or some selected portion of the cavities may be sealed with one layer with the other half or selected portion of the cavities sealed with another sheet or layer, different shaped cavities may use different seal layer, or the like. The seal layer 320 may have different physical properties, such as those covering the penetrating members 302 near the end of the cartridge may have a different color such as red to indicate to the user (if visually inspectable) that the user is down to say 10, 5, or other number of penetrating members before the cartridge should be changed out.

Referring now to Figure 7, another embodiment of the present invention will now be described. It should be understood that the analyte detecting members described herein may be designed for use with a cartridge such as that in Figure 6 or any other cartridge discussed herein. Thus, a plurality of analyte detecting members may be provided on a single cartridge. The cartridge may or may not have penetrating members also mounted on the cartridige. This embodiment provides a method for further lowering the minimum fluid sample volume used for a fluid device.

For example, in the present embodiment of the invention, to control the volume of blood or fluid sample, the height of the channel was decreased so that the volume was dropped to get 0.2μL from a starting sensor volume of 0.6μL. From a production point of view the opening of the channel with the dye cutting sometimes the channel got crimped. This can be overcome with another cutting process, only a limitation when producing the prototype. In one embodiment, the height of the channel was about 50 μm. In another embodiment, the design (3.0) has a shortened channel, and an increased height to 80 μm. This reduces any issues with high Hematocrit or high viscosity so that it was difficult to get the blood into the channel translating into no reading. There is only a 1% inconsistency of fill with the 80 μm. Some data has been acquired on this sensor. The volume of the sensor is 0.24 μL by calculation; there may be a variation, though they have shown that a variation in the height of the sensor does not affect the performance. To increase the efficiency of the system in terms of sample capture and measurement, the thought was to move to a lower volume requiring sensor configuration. The present invention improves volume without reducing the height of the channel because of the constraints with respect to the blood, and without shortening the channel..

To achieve lower volumes, one embodiment of the present invention using masking will now be described. This embodiment uses masking on 0.4 μL design, to achieve 0.1 μL volume. In this embodiment, the width of the channel is reduce to 500 μm by masking. Originally, the channel was 1000 μm. There is alignment of the 4 layers above the electrode. The present invention may fill in the gaps between the electrodes. The ratio of the height the electrodes and the dimension of the gap. In the configuration with a large (2000μm) working electrode and a large channel ( 500 μm gap), the situation for printing the layers is less stringent. The large electrode configuration is in the 4.3 strip. For the working electrode in the GSSC design, the working electrode is 500 μm and the gap is thinner (250μm). This is challenging because there may be undulations in the wall. However, this is now a 0.1 μL proposition. As seen in Figure 7, the size of the sample capturing structure in one form is 6.15 mm x 5 mm (without mesh, see Figure 7) as well as 7.75 mm x 5 mm (with mesh).

Referring now to Figures 8A-8C, an overview of the three different variants of sample capturing structures (enlarged structure) are shown. These sample capture structures wherein certain layers may be screen printed on to an analyte detecting member. The analyte detecting member may be on a strip or it may be part of a cartridge containing a plurality of analyte detecting members. Owing to the better handling as well as a using of a half-automatic stamping procedure, in some embodiments, the size of both structures were enlarged to 7.2 mm x 40 mm (see Figure 8B).

As seen in Figure 8A, one embodiment 350 is shown without mesh and both holes 352 have a diameter of about 1 mm. Referring now to Figures 8b and 9A, another embodiment will now be described. The Figure 8B shows one embodiment 360 with mesh 362. The device has a hole 364 in cover film 366 at about 1.0 mm in diameter. The diameter of the hole 368 in PVC support 370 is about 1.6 mm. The diameter of the hole 372 in PSA layer 374 is about 2.6 mm. These elements are more clearly illustrated in the exploded perspective view shown in Figure 9A.

Figure 8 C shows a still further embodiment 380 without mesh. The device has a hole 382 in cover film 366 at about 1.0 mm in diameter. The diameter of the hole 384 in PVC support 370 is about 1.6 mm. The diameter of the hole 386 in the PSA layer 374 is about 2.6 mm. These elements are more clearly illustrated in the exploded perspective view shown in Figure 9 A.

Referring now to Figures 10A- 1OC, cross-sections of other embodiments of the device will now be shown in further detail. In a variation of the device of Figure 8C (sip-in:GS-SC 4), this embodiment of Figure 1OA is also without mesh. The diameter of the hole 390 in the hydrophilic cover film 366 is about 1 mm. The diameter of the hole 392 in PVC support 370 is about 1 mm. The diameter of the hole 394 in PSA layer 374 is about 2.6 mm.

Referring now to Figure 1OB, in a still further variation of the device of Figure 8C (GS- SC 3*), this embodiment is without a mesh. The device has a hole 400 in the cover film 366 of about 1.6 mm in diameter. The diameter of the hole 402 in PVC support 370 is about 1.0 mm. The diameter of the hole 404 in PSA layer is about 2.6 mm. As seen in the figures, the hole 402 in the PVC support is smaller in size than those in other embodiments. However, the diameter of the hole 400 in the cover film is much larger. The various layers described above may be printed on to the analyte sensing device.

Generally, the dimension of the structures on the devices shown in the above figures may be as follows: 1) length of the capillary: 2.5 mm, 2) width of the capillary: 0.5 mm, 3) height of the capillary: 0.05 mm, and 4) volume of fluid for the analyte sensing device: 62.5 nl.

Referring now to Figure 10, the following figures show cross sections of GS-SC 3*, GS- SC 4 and GS-SC 1 (as labeled in the figure), clarifying the difference of the different sample capturing structures. The idea of GS-SC 4 is to have a structure consisting only of a capillary structure, at least. In that case, blood has contact to a capillary, the filling process happens very quickly. Using the sample capturing structure having the design of GS-SC 4 embodiment, blood has immediate contact to the capillary surrounding the drop of blood. A rapid and complete filling of GS-SC 4 has been observed. As seen in Figure 10, the sample capturing structure of GS-SC 3* (and also GS-SC 3) is more a mix of top-fill and sip-in. Referring now to Figure 1OC and 11, in the case of GS-SC 1 embodiment, the micro- capillary 420 may be formed between the PSA layer 374 and the hydrophilic cover film 366. In one case, the PSA layer 374 has been applied by using screen-printing. Due to the technique, the edge of the PSA layer are slightly curved (see Figure 11). This may be useful for the microcapillary. In addition, by using this sample capture structure the blood volume is lower than in comparison to the other structures.

It should be understood that various methods for manufacturing the analyte sensing devices shown herein will now be described. Any of the methods described below may be hi one embodiment, manufacturing of sample capturing structures (batch size: 10 sheets) may include I) drilling of holes into PVC-support, II) printing of the conductive lines: control of the resistance, III) printing of the insulating layer, IV) printing of reference and counter electrodes, V) printing of the working electrode (in one embodiment, the composition may be: 50% mediator / 100% buffer compounds / 50% GOD), VI) printing of the hydrophilic membrane (in one embodiment, the composition may be: PAA/CHAPS), VII) printing of the spacer layer (process-control: measurement of background and saturation current), VIII) printing of the

PSA-layer, IX) applying of mesh (for the mesh structure), X) applying of the cover film 126_2 having drilled holes, and XI) stamping process. Some embodiments may not involve drilling of holes (holes may be preformed).

To improve the success rate in an integrated system, some embodiments of the present invention may have a short connection between sample capturing structure and the sensor (one step production). One method of creating such a structure comprises of fabricating the sensor chamber and the sample capturing structure as the same layer. In one embodiment, the sample capturing structure consists of hydrophilic membrane layer, spacer layer and hydrophilic coated film. The hydrophilic layer and spacer layer may be screen printed for sensor chamber and sample capturing structure, hi the fabrication procedure there is only one additional step (drilling a hole) to get the integrated structure (analyte detecting member + SC).

Referring now to Figure 12, one embodiment of an analyte detecting member will now be described. Figure 12 shows the cross-section of one of the analyte detecting members 500. This embodiment has a hydrogel layer 510 formed on an electrode layer 512. The electrode layer 512 may be made of a carbon paste. In other embodiments, the electrode layer is made of a silver or silver chloride. The electrode layer 512, in this embodiment, includes a mediator. The hydrogel layer 510 may be used to stabilize the mediator in the layer 512. In some embodiments, the hydrogel layer 510 may be used to draw the mediator closer to the upper surface of the electrode layer 512. A conducting layer 514 may be formed under the electrode. The conducting layer 514 may form a trace that is used to provide an electrical contact with a meter or other device for measuring the analyte levels encountered by the analyte detecting member 500. A substrate 516 of a variety of shapes including but not limited to an elongate rectangle, square, circular disc, oval disc, triangle, square, polygonal, hexagonal, any single or multiple combinations of the above, or the like may be used to form the substrate which supports the conducting layer 514.

Referring now to Figure 13, another embodiment of an analyte detecting member will now be described. Figure 13 shows the cross-section of one of the analyte detecting members 520. This embodiment has a hydrogel layer 510 formed on an electrode layer 512. The electrode layer 524, in this embodiment, is a non-platinum material. Due to the high cost of the material, it is undesirable in some embodiments to include the platinum material. Printing of a paste of the electrode material with a mediator such a TMMP may not be suitable if platinum is used in a substantial amount. In some embodiments, trace amounts may be acceptable, but generally, this embodiments uses non-platinum electrodes. In some embodiments, the electrode layer 524 may include a mediator. The hydrogel layer 510 may be used to stabilize the mediator in the layer 524. hi some embodiments, the hydrogel layer 510 may be used to draw the mediator closer to the upper surface of the electrode layer 524. A conducting layer 514 may be formed under the electrode. The conducting layer 514 may form a trace that is used to provide an electrical contact with a meter or other device for measuring the analyte levels encountered by the analyte detecting member 500. A substrate 516 may be used to support the conducting layer 514.

Referring now to Figure 14, yet another embodiment of an analyte detecting member will now be described. Figure 14 shows the cross-section of one of the analyte detecting members 540. This embodiment has a hydrogel layer 542 without enzyme such as but not limited to GOD on an electrode layer 544. The electrode layer 544 may include a mediator or in some embodiments, may be without a mediator. In some embodiments, the electrode layer 544 may also include an enzyme such as but not limited to GOD or other enzyme may be in the electrode, but there will be no GOD in the hydrogel above the electrode. In some embodiment, the present invention is specific as to not have GOD in the hydrogel, but other non-GOD or GOD derivative enzymes maybe present. Some embodiments may include GOD in trace amounts that are insufficient for use in glucose monitoring. Referring now to Figure 15, another embodiment of an analyte detecting member will now be described. Figure 15 shows the cross-section of one of the analyte detecting member 560. This embodiment shows a sample capture structure 562 on a hydrogel layer 564. It should be understood that any of the sample capture structures such as but not limited to those described in Figures 8 to 11, may be combined with any of the various electrode and hydrogel layered devices described herein. The sample capture structures may promote a side, sip-in type structure, a top-fill type structure, or any combination of the two. Some may also incorporate mesh or wicking members to draw fluid toward the electrodes.

Referring now to Figure 16, yet another embodiment of the present invention is shown. This analyte detecting member 600 has a top-fill configuration. It includes an upper cover layer 602 and may include a hydrogel membrane 604 of the electrodes.

Figures 17 and 18 show still further embodiments which may have a side- fill configuration. These embodiments may include capillary channels as shown more clearly in Figures 19 and 20. It should be understood that these embodiments are purely exemplary and modifications may be made to vary the volume used for each analyte detecting member.

While the invention has been described and illustrated with reference to certain particular embodiments thereof, those skilled in the art will appreciate that various adaptations, changes, modifications, substitutions, deletions, or additions of procedures and protocols may be made without departing from the spirit and scope of the invention. For example, with any of the above embodiments, the low volume analyte detecting member may be used with any of the cartridges disclosed herein or in related patent applications. With any of the above embodiments, the sample capture structures may allow for side or sip-in introduction of the fluid to the analyte detecting member. The analyte detecting members may use volumes of less than 1 microliter, less than 500nl, 400nl, 30OnI₃ 200nl, 10OnI, 75nl, 60nl, 50nl, 40nl, 30nl, 20nl, IQnI, or less of body fluid. In some embodiments, the chamber that holds the body fluid over the electrodes is less than 1 microliter, less than 500nl, 400nl, 300nl, 200nl, 10OnI, 75nl, 60nl, 50nl, 40nl, 30nl, 20nl, lOnl, or less in volume, hi still other embodiments, the volume of the chamber over the electrodes is less than 1 microliter, less than 500nl, 400nl, 300nl, 200nl, 10OnI, 75nl, 60nl, 50nl, 40nl, 30nl, 20nl, IOnl, or less. Any of the features set forth in the present description may be combined with any other feature of the embodiments set forth above. Embodiments of the present invention may be designed for use with analyzing blood samples for glucose levels. The devices may be designed for very short periods of time such as by not limited to providing a glucose reading within 3 seconds of receiving blood. Other embodiments may be designed to provide readings within 4, 5, 6, 7, 8, 9, 10, 15, 20, 30, 40, 50, 60, or so seconds from the time blood contacts the electrode. It should be understood that with any of the configurations above, the design may be modified so that there is only a single hydrogel layer over the electrode. The hydrogel may be a 2D hydrogel. hi some embodiments, it may be a 3D hydrogel. Any of the analyte detecting members may be mounted on a cartridge which contains a plurality of analyte detecting members. Some embodiments may include placing the analyte detecting members on a disc or ribbon which follows the outer circumference or outline of the cartridge. It should be understood that embodiments of the present invention may be designed so as not to be used for extended periods of time or be implantable in a patient. The present invention may also have a hydrogel with pore sizes so as not to create poor porosity which would reduce the flux of glucose in the hydrogel. The present invention may desire to have good flux of glucose through the hydrogel. The present invention may provide a hydrogel that functions to create: a) stability for the mediator; b) wicking speed; c) high ratio between maximum current and background current. The present may be designed not have an outer membrane on top of the hydrogel layer. Some embodiments of the analyte detecting member may be designed not to have at least one of the following: carboxymethyl cellulose, Na-acrylate/acrylamide (in one embodiment this may be 4.2 M/3.1 M, pH 6), Dynol604, MDA , PBS buffer, or Darocure 1173.

The publications discussed or cited herein are provided solely for their disclosure prior to or concurrent with the filing date of the present application. Nothing herein is to be construed as an admission that the present invention is not entitled to antedate such publication by virtue of prior invention. Further, the dates of publication provided may be different from the actual publication dates which may need to be independently confirmed. All publications mentioned herein are incorporated herein by reference to disclose and describe the structures and/or methods in connection with which the publications are cited. U.S. Provisional Application Sr. No. 60/609,168 is fully incorporated herein by reference for all purposes.

Expected variations or differences in the results are contemplated in accordance with the objects and practices of the present invention. It is intended, therefore, that the invention be defined by the scope of the claims which follow and that such claims be interpreted as broadly as is reasonable.

Claims

WHAT IS CLAIMED IS:

1. An analyte detecting member comprising: a substrate; a plurality of conductive lines; and at least one working electrode and at least one counter electrode, each coupled to at least one conductive line.

2. An analyte detecting member comprising: a substrate; a plurality of conductive lines on said substrate; an insulating layer on said substrate; at least one working electrode and at least one counter electrode, each coupled to at least one conductive line; a cover film; a support layer; and a PSA layer wherein there is a hole in cover film wherein there is a hole in PVC support wherein there is a hole in PSA layer; wherein the detecting member is masked to reduce the volume required for the detecting member to operate is at least 40 nanoliters.

3. The device of claim 1 wherein diameter of the hole in cover film: is 1 mm, diameter of the hole in PVC support: 1.6 mm, and diameter of the hole in PSA layer: 2.6 mm.

4. The device of claim 1 further comprising a radial cartridge having a plurality of said analyte detecting members.

5. The device of claim 1 further comprising a ring having a plurality of said analyte detecting members.

6. A kit comprising: a device of claim 1 ; a lancing device, wherein said device of claim 1 is mounted on the lancing device; instructions for use instructing the user to apply no or minimal pressure against the device of claim 1 during lancing and applying pressure post lancing for spontaneous blood generation.

7. A method of reducing volume used in an analyte detection, the method comprising: masking a surface of an 0.4 μL analyte detecting member; and lowering the height of the cover to achieve 40 nL sample volume requirements.

8. The method of claim 7 further comprising providing a radial cartridge and forming a plurality of analyte detecting members on said cartridge.

9. The method of claim 7 further comprising providing a ring and forming a plurality of analyte detecting members on said ring.

10. The method of claim 7 further comprising: providing a ring and forming a plurality of analyte detecting members on said ring. coupling said ring to a cartridge containing a plurality of penetrating members.

11. A method of manufacturing an analyte detecting device, the method comprising: drilling of holes into PVC-support; printing of the conductive lines; printing of the insulating layer; printing of reference and counter electrodes; printing of the working electrode; printing of the hydrophilic membrane; printing of the spacer layer; printing of the PSA-layer; applying of mesh (for the mesh structure); applying of the cover film having drilled holes; and stamping.

12. The method of claim 11 wherein printing of the working electrode uses a composition: 50% mediator / 100% buffer compounds / 50% GOD.

13. The method of claim 11 wherein printing of the hydrophilic membrane using a composition: PAA/CHAPS.

14. The method of claim 11 further comprising in process-control: measurement of background and saturation current after printing spacer layer.

15. The method of claim 11 applying of the cover film having drilled holes.

16. The method of claim 11 control of the resistance when printing the conductive lines.

17. A method of manufacturing an analyte detecting device, said method comprising: providing a substrate; applying a plurality of layers of materials on said substrate, wherein said layers form an electrode device; and screen printing a hydrogel on said layers forming an electrode device, wherein said hydrogel is with a mediator.

18. A method of manufacturing an analyte detecting device, said method comprising: providing a substrate; applying a plurality of layers of materials on said substrate, wherein said layers form an electrode device; and screen printing a hydrogel on said layers forming an electrode device, wherein said hydrogel is without an enzyme.

19. A method of manufacturing an analyte detecting device, said method comprising: providing a substrate; applying a plurality of layers of materials on said substrate, wherein said layers form an electrode device; and screen printing a hydrogel on said layers forming an electrode device, wherein said hydrogel is without glucose oxidase.

20. A method of manufacturing an analyte detecting device, said method comprising: providing a substrate; applying a plurality of layers of materials on said substrate, wherein said layers form an electrode device; and screen printing a hydrogel containing a zwitterionic material on said layers forming an electrode device, wherein said electrode device comprises a non-platinum working electrode.

21. A method of manufacturing an analyte detecting device, said method comprising: providing a substrate; applying a plurality of layers of materials on said substrate, wherein said layers form an electrode device; and screen printing a hydrogel containing CHAPS or its derivatives on said layers forming an electrode device, wherein said electrode device comprises a non-platinum working electrode.

22. A method of manufacturing an analyte detecting device, said method comprising: providing a substrate; applying a plurality of layers of materials on said substrate; and screen printing a hydrogel on a layer of carbon paste, wherein said carbon paste contains a mediator and said hydrogel stabilizes said mediator in the carbon paste.

23. A method of manufacturing an analyte detecting device, said method comprising: providing a substrate; applying a plurality of layers of materials on said substrate; and screen printing a hydrogel on a layer of carbon paste, wherein said carbon paste contains a mediator and an enzyme.

24. A method of manufacturing an analyte detecting device, said method comprising: providing a substrate; applying a plurality of layers of materials on said substrate; and screen printing a hydrogel on a layer of carbon paste, wherein said carbon paste contains a mediator and an enzyme; wherein said hydrogel concentrates the mediator near a top layer of the carbon paste.

25. A method of manufacturing an analyte detecting device, said method comprising: providing a substrate; applying a plurality of layers of materials on said substrate; and screen printing a hydrogel on top of one of said layers, wherein said layer contains a mediator and an enzyme.

26. A method of manufacturing an analyte detecting device, said method comprising: providing a substrate; applying a plurality of layers of materials on said substrate; and screen printing a hydrogel on one of said layers, wherein said hydrogel contains a high molecular weight cross-linker (macromer) with a Mn greater than about 700 g/mol.

21. A. device comprising: a substrate; a plurality of layers of materials on said substrate; and a hydrogel on one of said layers, wherein the hydrogel is hydrophilic and is configured to stabilize a mediator in a layer immediately below the hydrogel.

28. A method of manufacturing an analyte detecting device, said method comprising: providing a substrate; applying a plurality of layers of materials on said substrate; and screen printing a hydrogel on one of said layers, wherein said hydrogel comprises PVP, CHAPS, Trinton X-IOO, a retarder, and an antifoam.

29. A method of manufacturing an analyte detecting device, said method comprising: providing a substrate; applying a plurality of layers of materials on said substrate; and screen printing only one layer of hydrogel on top of the electrode material.

30. A method of manufacturing an analyte detecting device, said method comprising: providing a substrate; applying a plurality of layers of materials on said substrate; screen printing a hydrogel on one of said layers; and applying a layer containing at least one mediator, said hydrogel being formed in contact with the one mediator; wherein the hydrogel layer is formed without GOD enzyme.

31. A method of manufacturing an analyte detecting device, said method comprising: providing a substrate; applying a plurality of layers of materials on said substrate; screen printing a hydrogel on one of said layers; and applying an electrode layer containing at least one mediator, said hydrogel being formed in contact with the one mediator in the layer.

32. The method of claim 31 wherein the electrode layer is formed without containing platinum.

33. The method of claim 31 wherein the hydrogel is a 2 dimensional hydrogel.

34. A method of manufacturing an analyte detecting device, said method comprising: providing a substrate; applying a plurality of layers of materials on said substrate; screen printing a hydrogel on one of said layers; and applying a layer containing at least one mediator, said hydrogel being formed in contact with the one mediator; wherein the hydrogel layer is formed directly over the working electrode.

35. A method of manufacturing an analyte detecting device, said method comprising: providing a substrate; applying a plurality of layers of materials on said substrate; screen printing a hydrogel on one of said layers; and applying a layer containing at least one mediator, said hydrogel being formed in contact with the one mediator.

36. The method of manufacturing without forming a cellulose acetate membrane.

37. The method of manufacturing wherein the hydrogel layer is formed directly over the working electrode.

38. A compound for use on an analyte detecting device, said compound comprising: a cross-linkable hydrophilic polymer dispersion containing a hydrophilic monomer mixture, a low molecular weight cross-linker and a hydrophilic high molecular weight polymer with an initiator.

39. The compound described in claim 38 wherein said compound is configured to allow rapid wicking of the analyte solution as well as rapid swelling of the resulting hydrogel membrane to allow a fast diffusion of the analyte to the enzyme.

40. A compound described in claim 38 wherein compound is configured to achieve highly cross-linked hydrogel to allow the permeation of low molecular weight analytes to the entrapped enzyme.