Nanostructured microelectrodes and biosensing devices incorporating the same

• US 8,888,969 B2
• Filed: 09/01/2009
• Issued: 11/18/2014
• 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: Soleymani, Leyla, Fang, Zhichao, Kelley, Shana, Sargent, Edward, Taft, Bradford
• Primary Examiner(s): Ball, J. Christopher
• Application Number:
  US13/061,465
• Publication Number:
  US 20110233075A1
• Time in Patent Office: 1,904 Days
• Field of Search: 977/924, 977/925, 977/754, 204280-293
• US Class Current: 204/289
• 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. A nanostructured microelectrode adapted to generate a charge in response to a biomolecular stimulus, wherein the nanostructured microelectrode is fractal.

2. The microelectrode of claim 1, wherein the microelectrode comprises 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 and a combination of any of the same.

3. The microelectrode of claim 1, wherein the charge is generated by means of an electrocatalytic reporter system.

4. The microelectrode of claim 3, wherein the electrocatalytic reporter system comprises ruthenium hexamine or potassium ferricyanide or combinations thereof.

5. The microelectrode of claim 1, wherein the biomolecular stimulus comprises nucleic acid hybridization or protein-to-protein binding.

6. The microelectrode of claim 1, 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.

7. The microelectrode of claim 1, wherein the microelectrode is defined lithographically.

8. The microelectrode of claim 1, comprising a biomolecular probe presented at a surface of the nanostructured microelectrode.

9. The microelectrode of claim 8, wherein the biomolecular stimulus comprises a complexation event between the biomolecular probe and a target molecule.

10. The microelectrode of claim 1, wherein the charge generated in response to the biomolecular stimulus is indicative of an amount of a target molecule detected by the nanostructured microelectrode.

11. A nanostructured microelectrode produced by a process comprising:

providing a substrate and an electrically conductive lead on the substrate, the lead having an insulated portion and an exposed portion; and

electrodepositing a conductive material on the exposed portion of the lead to obtain a fractal nanostructure.

12. The microelectrode of claim 11, wherein the electrodepositing comprises applying a potential in the range of about 0 mV to about −

250 mV.

13. The microelectrode of claim 11, wherein the electrodepositing is performed for a time duration in the range of about 25 s to about 500 s.

14. The microelectrode of claim 11, wherein the electrodepositing is performed using an electrolyte selected from the group consisting of:

H₂SO₄, HCl, and HClO₄.

15. The microelectrode of claim 11, wherein the exposed portion of the lead is defined lithographically.

16. The microelectrode of claim 15, wherein defining the exposed region lithographically comprises etching an aperture in an insulating layer to provide the exposed portion of the lead.

17. The microelectrode of claim 11, the process further comprising binding a probe molecule to the surface of the microelectrode such that the microelectrode is adapted to generate a charge in response to a biomolecular stimulus.