Claims
- 1. A device for affinity-base electrochemical detection of particles with single-particle sensitivity, including:
an electrode, a layer of insulation material on the electrode, said layer of insulation material including a well having a surface in contact with said electrode, said well of said layer having a surface-attached specific affinity component except on said surface in contact with said electrode.
- 2. The device of claim 1, wherein said well in said insulation material has a size corresponding to a target single-particle size.
- 3. The device of claim 1, wherein said surface-attached specific affinity components comprises a coating of an affinity ligand.
- 4. The device of claim 3, wherein said affinity ligand is selected from the group consisting of antibodies, combinatorial peptides, glycolipids, and amino acids.
- 5. The device of claim 1, wherein said electrode is a microelectrode having a specific geometry tailored for single-particle detection.
- 6. The device of claim 1, additionally including an encapsulation layer on said layer of insulation material except in an area adjacent said well.
- 7. The device of claim 6, additionally including a substrate and a layer of insulating material on said substrate, said electrode being located on said layer of insulating material.
- 8. The device of claim 7, wherein said substrate is composed of single crystalline silicon, said insulating material is composed of silicon nitride, said electrode is composed of Ti/Pt, said insulation material is composed of silicon nitride, said surface-attached specific affinity components comprises a bioaffinity coating, and said encapsulation layer is composed of polydimethylglutaramide (PMGI).
- 9. In a system for detecting single particles, the improvement comprising:
at least one device for affinity-based electrochemical detection with single-particle sensitivity.
- 10. The improvement of claim 9, wherein said at least one device includes a microelectrode, an insulation layer on the microelectrode and including an area wherein a portion of said microelectrode is exposed, and an affinity coating on a portion of said area of said insulator layer.
- 11. The improvement of claim 10, wherein said affinity coating comprises a ligand.
- 12. The improvement of claim 11, wherein said ligand is selected from the group of antibodies, combinatorial peptides, glycolipids, and amino acids.
- 13. The improvement of claim 10, wherein said area of said insulation layer comprises a well with a bottom area in contact with said microelectrode, and having a geometry similar to a target single-particle to be captured therein.
- 14. The improvement of claim 13, wherein surfaces of said well except for said bottom area are coated with said affinity coating.
- 15. The improvement of claim 9, additionally including a plurality of devices with single-particle sensitivity.
- 16. The improvement of claim 15, additionally including a capacitive read-out circuit operatively connected to said plurality of devices.
- 17. The improvement of claim 9, additionally including a capacitive read-out circuit operatively connected to said at least one of said devices.
- 18. A method for using at least one device for single-particle detection to achieve high sensitivity detection of specific particles, said method being selected from a group consisting of affinity assays with indirect electrochemical readout, creating controlled forces on particles to prevent non-specific binding and improve particle mixing and spatio-temporal tracking of particles.
- 19. The method of claim 18, wherein at least one device single-particle detection is positioned in a liquid medium for measurement of particles present or suspended in the liquid medium by the detection of selected affinity interactions.
Government Interests
[0001] The United States Government has rights in this invention pursuant to Contract No. DE-AC04-94AL85000 between the United States Department of Energy and the Sandia Corporation for the operation of the Sandia National Laboratories.