NANOSTRUCTURED MICROELECTRODES AND BIOSENSING DEVICES INCORPORATING THE SAME

• US 20110233075A1
• Filed: 09/01/2009
• Published: 09/29/2011
• Est. Priority Date: 09/02/2008
• Status: Active Grant

• Current Assignee: The Governing Council of the University of Toronto (University of Toronto)
• Original Assignee: The Governing Council of the University of Toronto (University of Toronto)
• Inventors: Taft, Bradford, Soleymani, Leyla, Kelley, Shana, Fang, Zhichao, Sargent, Edward
• Granted Patent: US 8,888,969 B2
• Time in Patent Office: Days
• US Class Current: 205/792
• CPC Class Codes: G01N 27/30 Electrodes, e.g. test electrodes; Half-cells G01N27/414 takes precedence
• 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: G01N 27/3275 Sensing specific biomolecules, e.g. nucleic acid strands, based on an electrode surface reaction
• CPC Class Codes: G01N 27/3278 involving nanosized elements, e.g. nanogaps or nanoparticles nanopores G01N33/48721; magnetic beads G01N27/745
• CPC Class Codes: G01N 33/5438 Electrodes
• CPC Class Codes: Y10S 977/754 Dendrimer, i.e. serially branching or "tree-like" structure
• CPC Class Codes: Y10S 977/925 Bioelectrical

Abstract

Nanostructured microelectrodes and biosensing devices incorporating the same are disclosed herein.

Claims

1-43. -43. (canceled)

44. A nanostructured microelectrode adapted to generate a charge in response to a biomolecular stimulus, wherein said nanostructure is spiky, rough or fractal.

45. The microelectrode of claim 44, said microelectrode is comprised of a material selected from the group consisting of:

a noble metal, an alloy of a noble metal, a conducting polymer, a metal oxide, a metal silicide, a metal nitride, carbon or a combination of any of the same.

46. The microelectrode of claim 44, wherein the charge is generated by means of an electrocatalytic reporter system.

47. The microelectrode of claim 46, wherein said electrocatalytic reporter system comprises ruthenium hexamine or potassium ferricyanide or combinations thereof.

48. The microelectrode of claim 44, wherein the biomolecular stimulus is nucleic acid hybridization or protein-to-protein binding.

49. The microelectrode of claim 44, further comprising a probe selected from the group consisting of:

thiolated probe molecules, nucleic acids, peptide nucleic acids, locked nucleic acids, or phosphorodiamidate morpholino oligomers terminated with thiols, nucleic acids, peptide nucleic acids, locked nucleic acids, amines, carboxylates, proteins or peptides functionalized with suitable tethering molecules and antibodies functionalized with suitable tethering molecules.

50. A biosensing device composing:

a substrate;

at least one electrically conductive lead on the substrate;

an insulating layer covering the lead, the insulating layer having an aperture exposing a portion of the lead;

a nanostructured microelectrode adapted by means of an electrocatalytic reporter system to generate a charge in response to a biomolecular stimulus;

at least one probe molecule attached to said microelectrode; and

wherein said microelectrode is in electrical communication with the exposed portion of the lead.

51. The biosensing device of claim 50, wherein the lead comprises a material selected from the group consisting of:

Au, Al, W, TiN, and polysilicon.

52. The biosensing device of claim 50, wherein the substrate comprises a material selected from the group consisting of:

silicon, silica, quartz, glass, sapphire, gallium arsenide, germanium, silicon carbide, indium compounds, selenium sulfide, ceramic, plastic, polycarbonate and other polymer or combinations thereof.

53. The biosensing device of claim 50, wherein the insulating layer is comprised of a material selected from silicon dioxide, silicon nitride, nitrogen doped silicon oxide, and parylene or combinations thereof.

54. The biosensing device of claim 50, wherein a plurality of microelectrodes is provided in an array, and each microelectrode is individually electronically accessible.

55. The biosensing device of claim 50, wherein the probe is selected from the group comprising:

nucleic acids, peptide nucleic acids, locked nucleic acids, proteins or peptides functionalized with suitable tethering molecules;

and wherein the biomolecular stimulus is nucleic acid hybridization or protein-to-protein binding.

56. A method of carrying out a biosensing process using a nanostructured microelectrode, said method comprising:

providing the device of claim 50;

biasing the microelectrode relative to a reference electrode;

measuring a reference charge or reference current flow between the microelectrode and the reference electrode;

exposing the microelectrode to a biomolecular stimulus;

measuring by means of the electrocatalytic reporter system, a charge or current flow generated at the microelectrode in response to the biomolecular stimulus; and

determining the amount of biomolecular stimulus present by comparing the measured charge or measured current flow against the reference charge or reference current flow.

57. A biosensing cartridge comprising:

a sample chamber containing a biological sample;

a biosensing chamber containing the biosensing device of claim 50.

58. The biosensing cartridge of claim 57, wherein the biosensing chamber comprises a buffer comprising sodium, phosphate, chloride, magnesium or combinations thereof.

59. The biosensing cartridge of claim 57, further comprises a purifying chamber for purifying or isolating the sample.

60. A method of detecting a biomolecular stimulus, said method comprising:

providing a nanostructured microelectrode adapted to generate a charge in response to a biomolecular stimulus, wherein said nanostructure is spiky or fractal, and wherein said microelectrode comprises a probe attached thereto;

biasing the microelectrode relative to a reference electrode;

measuring a reference charge or reference current flow between the microelectrode and the reference electrode;

exposing the microelectrode to a biological sample;

measuring by means of an electrocatalytic reporter system, a charge or current flow generated at the microelectrode in response to a biomolecular stimulus in said biological sample; and

determining the amount of biomolecular stimulus present by comparing the measured charge or measured current flow against the reference charge or reference current flow.

61. The method of claim 60, wherein the probe is selected from the group comprising:

nucleic acids, peptide nucleic acids, locked nucleic acids, proteins or peptides functionalized with suitable tethering molecules;

62. The method of claim 60, wherein the biomolecular stimulus is nucleic acid hybridization or protein-to-protein binding.

63. The method of claim 60, wherein the microelectrode is comprised of a material selected from the group consisting of:

a noble metal, an alloy of a noble metal, a conducting polymer, a metal oxide, a metal silicide, a metal nitride, carbon or a combination of any of the same.

64. The method of claim 60, wherein the biological sample comprises a tissue sample, cell culture isolate, blood, plasma, serum, cerebrospinal fluid, lymph, tears, urine, saliva mucus, or combinations thereof.

65. A method of detecting the presence of a biomarker in a biological sample, comprising:

providing a nanostructured microelectrode adapted to generate a charge in response to a hybridization or protein-to-protein interaction event, wherein said nanostructure is spiky or fractal, and wherein said microelectrode comprises a probe, said probe capable of hybridizing or binding to the biomarker of interest;

biasing the microelectrode relative to a reference electrode;

measuring a reference charge or reference current flow between the microelectrode and the reference electrode;

exposing the microelectrode to the biological sample;

measuring by means of an electrocatalytic reporter system, a charge or current flow generated at the microelectrode in response to the hybridization or interaction of the probe with the biomarker of interest,

wherein the presence of a charge or current flow as compared to the reference is indicative of the presence of the biomarker of interest.

66. The method of claim 65, wherein the probe is selected from the group comprising:

nucleic acids, peptide nucleic acids, locked nucleic acids, proteins or peptides functionalized with suitable tethering molecules;

67. The method of claim 65, wherein the microelectrode is comprised of a material selected from the group consisting of:

a noble metal, an alloy of a noble metal, a conducting polymer, a metal oxide, a metal silicide, a metal nitride, carbon or a combination of any of the same.

68. The method of claim 65, wherein the biological sample comprises a tissue sample, cell culture isolate, blood, plasma, serum, cerebrospinal fluid, lymph, tears, urine, saliva mucus, or combinations thereof.

69. The method of claim 65, wherein the biomarker of interest is a gene over-expressed in cancer cells.

70. The method of claim 65, wherein the biomarker of interest is a viral gene.