ELECTROCHEMICAL SENSOR AND METHOD FOR MANUFACTURING

• US 20110203941A1
• Filed: 08/28/2008
• Published: 08/25/2011
• Est. Priority Date: 08/30/2007
• Status: Active Grant

• Current Assignee: Pepex Biomedical, Inc.
• Original Assignee: Pepex Biomedical, LLC
• Inventors: Say, James L.
• Granted Patent: US 9,044,178 B2
• Time in Patent Office: Days
• US Class Current: 205/775
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14865 invasive, e.g. introduced into the body by a catheter or needle or using implanted sensors
• CPC Class Codes: G01N 27/3272 Test elements therefor, i.e. disposable laminated substrates with electrodes, reagent and channels optical biosensors G01N33/52

Abstract

A sensor includes a sheath that is elongated along a longitudinal axis; a spacer positioned within the sheath and defining first and second channels having lengths that extend along the longitudinal axis; a first elongated member positioned within the first channel; and a second elongated member positioned within the second channel. The first elongated member includes an active surface forming a working electrode and the second elongated member including an active surface defining a counter electrode.

Claims

1-35. -35. (canceled)

36. A sensor comprising:

an insulating sheath that is elongated along a longitudinal axis;

a spacer positioned within the insulating sheath, the spacer defining first and second channels having lengths that extend along the longitudinal axis;

a first elongated member positioned within the first channel, the first elongated member including an active surface, the active surface forming a working electrode; and

a second elongated member positioned within the second channel, the second elongated member including an active surface defining a counter electrode;

wherein the spacer is sized and configured to support the insulating sheath to provide voids between the insulating sheath and the active surfaces of the electrodes, whereby a test sample can reach the active surfaces within the sheath by passing through the voids.

37. The sensor of claim 36, wherein the spacer further defines a third channel in which a third elongated member is positioned, the third elongated member including an active surface defining a reference electrode.

38. The sensor of claim 36, wherein the active surfaces of the elongated members project outwardly from the sheath and face radially outwardly from the channels of the spacer.

39. The sensor of claim 36, wherein the sheath extends around the active surfaces and defines an open end to facilitate access to the active surfaces.

40. The sensor of claim 36, wherein the spacer is constructed of a dielectric material.

41. The sensor of claim 36, wherein the active surface of the first elongated member is coated with a sensing layer that is hydrated when the active surface of the first elongated member is immersed within a test volume.

42. The sensor of claim 41, wherein the first elongated member includes a dielectric core surrounded by a conductive layer, which is covered by the sensing layer.

43. The sensor of claim 36, wherein each elongated member includes a composite nylon monofilament conductive thread material.

44. A method of sensing an analyte in a test volume of a sample, the method comprising:

providing a sensor having a sensing tip, the sensor including a spacer separating an elongated working electrode and an elongated counter electrode arranged within an insulating sheath, the working electrode including an active surface coated with a sensing layer, wherein the spacer and the electrodes project axially beyond the insulating sheath to form the sensing tip;

immersing the sensing tip of the sensor within a test volume of a sample, whereby the test sample diffuses into the sensing layer;

applying a voltage potential between the working electrode and the counter electrode; and

measuring any current flow generated when applying the voltage.

45. The method of claim 44, wherein immersing the sensing tip of the sensor within the test volume of the sample comprises hydrating the sensing layer coating the active surface of the working electrode.

46. An electro-chemical sensing device comprising:

a conductive member having an outer surface;

a sheath covering the conductive member, the sheath having a thickness defined between inner and outer boundaries of the sheath, the inner boundary of the sheath being located at the outer surface of the conductive member, the sheath defining a plurality of side openings that extend through the thickness of the sheath from the inner boundary to the outer boundary, each of the side openings having a longitudinal axis that extends radially outwardly from the conductive member; and

sensing chemistry positioned within the side openings.

47. The electro-chemical sensing device of claim 46, wherein the conductive member includes a dielectric core surrounded by a conductive layer.

48. The electro-chemical sensing device of claim 46, wherein the inner boundary of the sheath is configured to inhibit a test sample from moving along a length of the conductive member in a region between the sheath and the conductive member.

49. The electro-chemical sensing device of claim 46, wherein the side openings are generally cylindrical in shape.

50. The electro-chemical sensing device of claim 46 wherein the side openings have diameters less than about 100 microns.

51. The electro-chemical sensing device of claim 46, wherein the sensing chemistry within each side opening is electrically connected to the conductive member.

52. The electro-chemical sensing device of claim 46, wherein the sensing chemistry within each opening includes solid rods extending outwardly from the conductive member in a radial direction at least partially through the opening.

53. The electro-chemical sensing device of claim 46, wherein the sensing chemistry within each opening includes hollow structures lining the opening, the hollow structures being electrically connected to the conductive member.

54. The electro-chemical sensing device of claim 53, wherein each side opening of the sheath is lined by a conductive layer surrounding the hollow structure to provide an electrical pathway for carrying current radially through the sheath between the conductive member and the sensing chemistry.

55. The electro-chemical sensing device of claim 54, wherein the sheath includes an inner dielectric layer surrounded by an electrically conductive surface layer.