ELECTROCHEMICAL SYSTEM FOR MEASURING A BIOLOGICAL COMPOUND BY AN ENZYME

• US 20100018866A1
• Filed: 07/10/2007
• Published: 01/28/2010
• Est. Priority Date: 07/25/2006
• Status: Active Grant

• Current Assignee: The Swatch Group Research And Development Ltd
• Original Assignee: The Swatch Group Research And Development Ltd
• Inventors: Borgmann, Sabine, Schuhmann, Wolfgang
• Granted Patent: US 8,951,404 B2
• Time in Patent Office: Days
• US Class Current: 205/777.500
• CPC Class Codes: C12Q 1/004 mediator-assisted
• CPC Class Codes: C12Q 1/006 for glucose
• CPC Class Codes: G01N 27/3272 Test elements therefor, i.e. disposable laminated substrates with electrodes, reagent and channels optical biosensors G01N33/52

Abstract

The system includes an electronic measuring apparatus for receiving an electrochemical sensor including a substrate that carries the current collectors for connecting the measuring and reference electrodes to the measuring apparatus. The measuring electrode is coated with a reagent including at least the specific enzyme of the biological compound to be analysed in a body fluid. The measuring apparatus can impose at least two different temperatures to enable the signal from the compound to be analysed from those of other biological compounds interfering with the signal. Application to measuring glucose in the blood with glucose dehydrogenase as the enzyme, without interference with maltose.

Claims

1-21. -21. (canceled)

22. A system for measuring a determined biological compound in a body fluid sample by electrochemical measurements using a specific enzyme of said biological compound but which can interfere with other biological compounds, wherein it includes:

an electrochemical sensor including a substrate carrying current collectors for connecting a measuring apparatus to at least one measuring electrode and a reference electrode, said measuring electrode being coated with a reagent including at least the specific enzyme;

means for bringing the measuring electrode to at least two determined temperatures;

a measuring apparatus for receiving the sensor connected to an electrical power source and including an electronic circuit for controlling said means for bringing the measuring electrode to at least two different temperatures and for imposing a variable or non-variable intensity, or a variable or non-variable voltage, between the electrodes, and a device for exploiting the signals supplied by said sensor, arranged for differentiating the signal belonging to the determined biological compound from the signals resulting from interference with other biological compounds.

23. The measuring system according to claim 22, wherein the means for bringing the measuring electrode to at least two determined temperatures are formed by a heating coil embedded in the thickness of the sensor and extending underneath the measuring electrode.

24. The measuring system according to claim 22, wherein the heating means are formed by a heating coil integrated in the measuring apparatus and positioned underneath the measuring electrode when the sensor is inserted into said measuring apparatus.

25. The measuring system according to claim 23, wherein the heating means are powered by a pulsed or non-pulsed current for bringing the measuring electrode to at least two different temperatures.

26. The measuring system according to claim 22, wherein the substrate is made of ceramic or similar material.

27. The measuring system according to claim 22, wherein the substrate is made of a plastic material that can withstand temperatures that do not exceed 50°

C.

28. The measuring system according to claim 23, wherein the substrate is formed by:

an insulating bottom substrate carrying the heating means and their means of connection to the measuring apparatus,

an insulating intermediate substrate carrying at the surface thereof the electrodes and their means of connection to the measuring apparatus, and

an insulating top substrate leaving apertures free for the electrodes and the connecting zones.

29. The measuring system according to claim 22, wherein the reagent is deposited on the measuring electrode of the sensor by anodic electrodeposition.

30. The measuring system according to claim 22, wherein the specific enzyme enters into the composition of the reagent by being linked by a cofactor.

31. The measuring system according to claim 22, wherein the reagent further includes a mediator facilitating the transfer of electrons between said specific enzyme and the measuring electrode.

32. The measuring system according to claim 22 for measuring the blood glucose level, wherein the specific enzyme is glucose dehydrogenase.

33. The measuring system according to claim 32, wherein glucose dehydrogenase is present in the reagent with pyrroloquinoline quinone as the cofactor (PQQ-sGDH).

34. The measuring system according to claim 31, wherein the mediator entering into the composition of the reagent is chosen from between a ferrocene derivative and an osmium complex.

35. The measuring system according to claim 32, wherein it can differentiate a signal belonging to glucose from an interference signal with other saccharides, oligosaccharides or oligopolysaccharides, such as maltose.

36. The measuring system according to claim 22, wherein the electrochemical measurements are carried out by amperometrics by imposing a voltage comprised between 0 and 500 mv between the electrodes, depending upon the construction features of the sensor.

37. The measuring system according to claim 22, characterized in the that measuring apparatus further includes a display screen for displaying the glucose level.

38. The measuring system according to claim 37, wherein the measuring apparatus further includes a memory for displaying the result of the measurement being carried out, compared to prior measurements, said display being able to be made, for example, in the form of a graph.

43. The measuring system according to claim 32, wherein the mediator entering into the composition of the reagent is chosen from between a ferrocene derivative and an osmium complex.

39. A method for measuring a determined biological compound in a body fluid by electrochemical measurements using a specific enzyme of said biological compound, but which can interfere with other biological compounds, including the steps consisting in:

depositing a sample of said body fluid on the measuring zone of an electrochemical sensor including a reference electrode and a measuring electrode coated with a reagent including at least the specific enzyme,

introducing the sensor into a measuring apparatus connected to an electrical power source and including an electronic circuit, which imposes a variable or non variable intensity, or a variable or non variable voltage, between the electrodes, and means for bringing the measuring electrode to at least two different temperatures,

submitting the signals obtained, at least two different temperatures, to an exploitation device for differentiating the signal belonging to the determined compound from the signals resulting from interference with other biological compounds.

40. The method according to claim 39, wherein the means for bringing the measuring electrode to two different temperatures are formed by heating coils integrated in the sensor or in the measuring apparatus.

41. The method according to claim 39, wherein the exploitation device includes a programme for processing signal via multiple linear regression.

42. An electrochemical sensor for measuring a determined biological compound in the blood using a specific enzyme of said biological compound, including at least one reference electrode and one measuring electrode coated with a reagent including at least said specific enzyme, wherein said sensor further includes a heating coil arranged underneath the measuring electrode and electrically insulated therefrom, in the measuring zone, at least two different temperatures enabling the signal belonging to the determined biological compound to be differentiated from the interference signals with other biological compounds.