Electrochemical sensor and method thereof

• US 20020157947A1
• Filed: 12/07/2001
• Published: 10/31/2002
• Est. Priority Date: 03/23/2001
• Status: Active Grant

• Current Assignee: Applied Biomedical, LLC
• Original Assignee: Virotek LLC
• Inventors: Rappin, Craig, Hajizadeh, Kiamars, Mills, Kelly
• Granted Patent: US 6,572,745 B2
• Time in Patent Office: Days
• US Class Current: 204/403.01
• CPC Class Codes: G01N 27/3272 Test elements therefor, i.e. disposable laminated substrates with electrodes, reagent and channels optical biosensors G01N33/52
• CPC Class Codes: Y10T 29/49002 Electrical device making

Abstract

A sensor is provided for the determination of various concentrations of one or more components within a fluid sample. The sensor includes an injection molded body, at least two electrodes, an enzyme, and if desired, an electron transfer mediator. The body includes a reaction zone for receiving a fluid sample. The electrodes are at least partially embedded within the plastic body and extend into the reaction zone. Also contained within the reaction zone is an enzyme capable of catalyzing a reaction involving a compound within the fluid sample. Additionally, the sensor incorporates fill detection which activates a meter, attached to the sensor, for measuring the electrochemical changes occurring in the reaction zone.

Claims

29. An electrochemical device for cooperating with an electronic meter capable of measuring the electrochemical properties in a fluid sample resulting from chemical or enzymatic reaction, comprising:

a body of insulative material with a first end and a second end;

three electrically conductive electrodes spaced apart in fixed longitudinal relation to each other, housed in the body;

a plug for connecting a meter to the body;

means for receiving a fluid sample in the body; and

means for detecting when a sufficient amount of fluid sample has been received for analysis.

50. An electrochemical device for measuring the concentration of an analyte by cooperating with an electronic meter capable of measuring the electrochemical properties of a fluid sample resulting from chemical or enzymatic reaction, comprising:

a unitary, single molded plastic body with two opposing ends;

at least two spaced apart electrically conductive electrodes housed in the molded body;

a plug formed at one end of the body exposing the electrodes outside the body for connecting the meter to the housing;

an inlet molded into the other end of the housing defining a capillary for drawing the fluid sample into the body upon contact with the fluid sample;

a reaction zone in communication with the capillary, the reaction zone having an interior surface and at least a portion of each electrode exposed therein for reacting with the fluid sample, such that sample drawn into the reaction zone contacts the exposed portion of at least one electrode and activates the meter to indicate sufficient fill; and

means for treating at least one of the interior surface of the reaction zone and at least one of the electrodes with one or more substances that react with the fluid sample to produce electrochemical changes measurable by the meter.

51. The electrochemical device of claim 50 wherein the reaction zone has a volume defined by the shape of at least one of the body and an end cap securedly affixable to the body.

52. The electrochemical device of claim 50 wherein the electrodes are embedded

in the body as one of isolated conductive wires or a composite conductive plate.

53. The electrochemical device of claim 50 wherein at least one aperture is formed in the body between a top surface and a bottom surface to permit holding of the electrodes during the molding of the body.

54. The electrochemical device of claim 50 having

a hinge constructed in the body permitting the pivoting and connecting of a portion of the body onto itself;

and

at least one protuberance formed in the body on one side of the hinge to mate with at least one recessed surface in the body on the other side of the hinge to form the reaction zone.

55. The electrochemical device of claim 50 having

a hinge constructed in the body permitting the pivoting and connecting of a portion of the body onto itself;

and

at least one energy director ridge formed in the body on at least one side of the hinge, the energy director ridge being securedly affixable to the body opposite side of hinge to form the reaction zone.

56. The electrochemical device of claim 50 wherein at least one aperture is formed in the body in communication with the reaction zone for treating one or more electrodes in the molded body.

57. The electrochemical device of claim 50 wherein the means for treating is a coating having at least an enzyme.

58. The electrochemical device of claim 50 wherein the coating includes one of an enzyme-antibody conjugate and an enzyme-analyte conjugate.

59. The electrochemical device of claim 50 wherein the coating includes an electron mediator.

60. A sensor comprising:

a body having an end for cooperating with a meter and an end for receiving a fluid sample;

a plurality of electrically conductive leads at least partially embedded within the body and having at least one lead extending into the end for receiving the fluid sample;

a cavity in the body to detect sufficiency of sample quantity; and

,

an enzyme deposited on at least one of the leads.

1. An electrochemical device for cooperating with a meter to measure changes in electrochemical properties of a fluid sample as a result of chemical or enzymatic reactions, comprising:

(a) a body of insulative material with a first end and an opposing second end;

(b) at least two electrically conductive electrodes disposed in fixed longitudinal relation in the insulative material;

(c) means for connecting a meter to the body;

(d) means for receiving a fluid sample;

(e) means for detecting when a sufficient amount of fluid sample has been received; and

,

(f) means for treating at least one of the electrodes with one or more substances such that the substances react with the fluid sample to produce electrochemical changes correlative to the concentration of an analyte in the sample.

2. The electrochemical device of claim 1 wherein the body is a unitary, single piece of molded plastic and the electrodes are substantially molded into the plastic.

3. The electrochemical device of claim 1 wherein the body comprises an electrode housing and an end cap pivotably attached to the electrode housing at the first end of the body, both the electrode housing and the end cap are molded plastic.

4. The electrochemical device of claim 1 wherein the body has a hinge at the first end for permitting at least a portion of the body on one side of the hinge to pivot and connect onto a portion of the body on the other side of the hinge.

5. The electrochemical device of claim 4 further comprising at least one ridge and one recessed surface, each formed in the device on opposite sides of the hinge, such that when the body is pivoted about the hinge, said ridge and said recessed surface mate to form a reaction zone in the body.

6. The electrochemical device of claim 3 further comprising at least one protuberance formed on at least one of the housing and the end cap, such that the end cap may be pivoted onto the housing and securedly attached thereto to form a reaction zone in the body.

7. The electrochemical device of claim 1 wherein the means for connecting a meter is at the second end of the body.

8. The electrochemical device of claim 1 wherein the means for connecting a meter is a plug formed at the second end of the body.

9. The electrochemical device of claim 1 wherein the means for receiving a fluid sample is a capillary inlet molded into the first end for drawing the fluid sample into the body upon contact with the sample.

10. The electrochemical device of claim 9 further comprising a reaction zone formed in the body in communication with the capillary inlet.

11. The electrochemical device of claim 10 wherein the reaction zone is a channel containing at least a portion of each of the electrodes for analyzing the fluid sample drawn therein.

12. The electrochemical device of claim 11 wherein the means for detecting sufficient fill includes a depressurization vent formed in the body in communication with the reaction zone.

13. The electrochemical device of claim 11 wherein the means for detecting sufficient fill includes a sample fill vent in the body in communication with the reaction zone for filling with sample fluid and allowing for fill detection to be made visually.

14. The electrochemical device of claim 11 having an end cap pivotably attached to the body near the first end, the end cap having a vent that upon securing the end cap to the body, the sample fill vent substantially aligns with at least one of the electrodes.

15. The electrochemical device of claim 10 wherein the at least two electrodes terminate in the reaction zone, the reaction zone having a vent for relieving pressure.

16. The electrochemical device of claim 11 wherein the reaction zone lies in the bottom portion of the device.

17. The electrochemical device of claim 1 wherein the electrodes are conductive wires.

18. The electrochemical device of claim 17 wherein at least one wire is coated with a conductive material different from that of the wire.

19. The electrochemical device of claim 1 wherein the electrodes are formed from a conductive plate.

20. The electrochemical device of claim 1 wherein at least one aperture is formed in the body to permit holding of the electrodes during molding of the body.

21. The electrochemical device of claim 1 wherein at least one aperture is formed in a top surface of the body to permit holding of the electrodes during molding of the body.

22. The electrochemical device of claim 1 wherein at least one aperture is formed in a bottom surface of the body to permit holding of the electrodes during molding of the body, and then sealed after the body is molded.

23. The electrochemical device of claim 1 wherein the body has a top surface, a bottom surface, at least one upper aperture formed in the top surface, and at least one lower aperture formed in the bottom surface, and at least one of the apertures is sealed after the body is molded

24. The electrochemical device of claim 10 wherein at least one aperture is formed in the body in communication with the reaction zone to treat one or more electrodes after the molding thereof.

25. The electrochemical device of claim 1 wherein the means for treating one or more electrodes is the coating of at least one electrode with at least one of a reagent and an enzyme.

26. The electrochemical device of claim 1 wherein an enzyme is applied to the outer surface of one of the electrodes.

27. The electrochemical device of claim 26 wherein one of an enzyme-antibody conjugate or an enzyme-analyte conjugate is applied to another of the electrodes.

28. The electrochemical device of claim 27 wherein an electron mediator is applied to one or more of the electrodes.

30. The electrochemical device of claim 29 wherein the plug has a portion of the electrodes exposed outside the body.

31. The electrochemical device of claim 29 wherein the body includes an electrode encasing unit and an end cap, attached to one another with each being made of molded plastic.

32. The electrochemical device of claim 29 wherein the body is unitary and one piece, made of molded plastic.

33. The electrochemical device of claim 32 wherein the means for receiving a fluid sample includes a capillary inlet for drawing the fluid sample into the body upon contact with the fluid sample.

34. The electrochemical device of claim 33 further having

a hinge constructed in the body permitting the pivoting and connecting of a portion of the body onto itself;

and

at least one energy director ridge formed in the body on at least one side of the hinge, such that securedly affixing the energy director ridge to the body opposite side of hinge forms a reaction zone.

35. The electrochemical device of claim 34 further comprising means for treating one or more electrodes with one or more substances for reacting with the fluid sample to produce electrochemical changes measurable by the electrodes.

36. The electrochemical device of claim 34 wherein the means for treating one or more electrodes is coating at least one electrode with at least one of a reagent and an enzyme.

37. The electrochemical device of claim 34 wherein an enzyme is applied to the outer surface of one of the electrodes.

38. The electrochemical device of claim 37 wherein an electron mediator is applied to the outer surface of one or more of the electrodes.

39. The electrochemical device of claim 33 having

a hinge constructed in the body permitting the pivoting and connecting of a portion of the body onto itself;

and

at least one protuberance formed in the body on one side of the hinge to mate with at least one recessed surface in the body on the other side of the hinge.

40. The electrochemical device of claim 39 further comprising means for treating one or more electrodes with one or more substances for reacting with the fluid sample to produce electrochemical changes measurable by the electrodes.

41. The electrochemical device of claim 39 wherein the means for treating one or more electrodes is coating at least one electrode with at least one of a reagent and an enzyme.

42. The electrochemical device of claim 39 wherein an enzyme is applied to the outer surface of one of the electrodes.

43. The electrochemical device of claim 42 wherein an electron mediator is applied to the outer surface of one or more of the electrodes.

44. The electrochemical device of claim 29 wherein the means for detecting sufficient fill includes

a reaction zone formed in the body, the reaction zone having at least a portion of each electrode exposed therein for reacting with the fluid sample, such that sample drawn into the reaction zone contacts the exposed portion of at least one of the electrodes and activates the meter to indicate sufficient fill.

45. The electrochemical device of claim 44 wherein the reaction zone is in fluid communication with a capillary inlet.

46. The electrochemical device of claim 29 wherein the electrodes are one of isolated conductive wires or wires associated with a conductive plate.

47. The electrochemical device of claim 29 wherein at least one aperture is formed in the body to permit holding of the electrodes during the molding of the body.

48. The electrochemical device of claim 29 wherein at least one transverse passageway between a top surface and a bottom surface of the body is formed to permit holding of the electrodes during the molding of the body.

49. The electrochemical device of claim 29 wherein at least one aperture is formed in the body in communications with the reaction zone to allow at least one of the electrodes to be chemically treated after the molding thereof.

61. The sensor of claim 60 wherein the body is formed from a moldable material and made in a mold.

62. The sensor of claim 60 wherein the leads are at least partially exposed at the end for cooperating with the meter.

63. The sensor of claim 60 wherein the cavity is formed in the lower portion of the body and communicates with the end for receiving the fluid sample, such that the fluid sample contacts a portion of the leads to produce a measurable change in the fluid.

64. The sensor of claim 60 wherein at least one of the leads is a wire conductor.

65. The sensor of claim 60 wherein at least one of the leads is a stamped conductive metal member.

66. The sensor of claim 65 wherein the stamped conductive metal member is coated with another electrically conductive material.

67. The sensor of claim 60 wherein at least two of the leads include different metals.

68. The sensor of claim 60 wherein the body has a plurality of guides molded therein to prevent the leads from moving within the body.

69. The sensor of claim 60 wherein the end for receiving a fluid sample includes a capillary inlet.

70. The sensor of claim 69 wherein the capillary inlet is in communications with the cavity for detecting sufficient fill.

72. The sensor of claim 70 wherein the cavity and the leads are in a bottom portion of the sensor, such that the sample contacts the edges of the leads to produce a measurable electrical change in the fluid.

73. The sensor of claim 70 wherein at least one of the leads is a stamped conductive metal member.

74. The sensor of claim 70 wherein the stamped conductive metal member is coated with an electrically conductive material different from the lead.

75. The sensor of claim 70 wherein the body has a plurality of guides molded therein to hold and maintain the leads within the body.

76. The sensor of claim 70 wherein the enzyme is disposed on at least one of the leads.

80. The sensor of claim 73 wherein the sample receiving zone has a capillary inlet for drawing a fluid sample.

71. A sensor comprising:

an injection molded plastic body having a meter-attachment end and a fluid sample receiving cavity;

a plurality of electrically conductive leads at least partially embedded within the body with at least one lead extending from the attachment end to the fluid sample receiving cavity;

a plurality of vents communicating with the fluid sample receiving cavity for detecting the sufficiency of the amount of the fluid sample received; and

,

an enzyme disposed within the fluid sample receiving cavity.

72-1. The sensor of claim 70 wherein the leads are at least partially exposed at the attachment end of the molded body.

77. A sensor for analyzing a fluid sample comprising:

an injection molded body having an attachment end and a sample receiving zone,

a plurality of electrically conductive leads at least partially embedded within the body, the leads extending in substantial alignment between the two ends, at least one of the leads extending into the sample receiving zone,

a substance deposited within the sample receiving zone for analyzing the fluid sample; and

,

a vent communicating with the sample receiving zone for determining adequate sample fill;

such that the sample contacts a portion of the leads to produce a measurable change in the sample, the change being correlative to the concentration of an analyte in the sample.

78. The sensor of claim 77 wherein the substance is one of an enzyme.

79. The sensor of claim 77 wherein the body has a plurality of guides molded therein with at least one of the guides abutting against at least one of the leads.

82. The method of claim 78 wherein the molding step comprises molding the body in two pieces, an electrode-encasing housing and an end cap, both of the pieces being hingeably attachable to one another after the molding is completed.

83. The method of claim 78 wherein the molding step molds the body into a unitary, single piece.

84. The method of claim 78 further comprising constructing a hinge in the body to permit the pivoting and connecting of a portion of the body onto itself.

85. The method of claim 78 wherein the molding step comprises forming at least one protuberance in a portion of the body on one side of the hinge and at least one trough in a portion of the body on the opposite side of the hinge for mating with the at least one protuberance when at least one of the sides is folded about the hinge.

86. The method of claim 78 wherein the molding step includes forming a capillary inlet into one end of the body, a reaction zone in communication with the capillary inlet, and a vent in communication with the reaction zone.

87. The method of claim 78 wherein the molding step is done using at least one electrode coated with a conductive material different from the electrode.

88. The method of claim 78 wherein the molding step includes forming at least one aperture in the body.

89. The method of claim 85 wherein the at least one aperture is formed in a top surface of the body.

90. The method of claim 85 wherein the at least one aperture is formed in a bottom surface of the body.

91. The method of claim 90 further including forming at least one aperture in a bottom surface of the body, each said aperture being substantially aligned with the at least one aperture formed in a bottom surface to permit holding of the electrodes during the molding of the body.

81. A method of making an electrochemical device for cooperating with a meter capable of measuring electrochemical changes occurring in a fluid sample when subjected to an electrical current, comprising the steps of:

positioning at least two spaced apart electrically conductive electrodes in a mold;

molding a body of insulative material around the electrodes to produce a body having two ends, one of the ends having means for receiving a fluid sample, the body further including means for activating the meter upon receipt of an adequate amount of the sample; and

,

treating at least one of the electrodes with one or more substances for reacting with the fluid sample to produce measurable changes in the electrical properties of the sample.

92. A method of making an electrochemical device for cooperating with a meter capable of measuring the difference between the electrical properties of at least two electrically conductive electrodes, comprising the steps of:

positioning at least two spaced apart electrically conductive electrodes in a mold;

molding a body of insulative material with two ends around the electrodes with one end having therein means for receiving a fluid sample and an aperture in the body in communication with at least one of the electrodes, the body further having means for detecting the presence of an adequate amount of sample; and

,

after molding treating at least one of the electrodes with one or more chemicals to change the electrical properties of the treated electrode upon contact with a fluid sample after the molding of the body.