Microchip structure and treatments for electrochemical detection
Disclosed herein are processes and devices for use in the electrochemical detection of a target in a sample. For example, silicon or glass surfaces are treated with silanes functionalized with various side chains to tune the surface wetting characteristics.
1. A process for the manufacture of a biosensing device, the process comprising:
providing a substrate having an electrically conductive lead on a surface thereof;
applying an insulating layer to the substrate and the electrically conductive lead, said insulating layer comprising one or more of silicon dioxide and silicon nitride;
etching an aperture in the insulating layer to expose a portion of the electrically conductive lead onto which a nanostructured microelectrode is to be plated;
oxidizing one or more of the silicon dioxide and the silicon nitride to form oxidized silicon dioxide or oxidized silicon nitride;
allowing one or more of the oxidized silicon dioxide and the oxidized silicon nitride to react with a functionalized silane; and
forming a self-assembled monolayer of the functionalized silane on the insulating layer.
2. The process of claim 1 , wherein the insulating layer comprises a layer of silicon dioxide and a layer of silicon nitride.
3. The process of claim 2 , wherein the layer of silicon dioxide is disposed between the substrate and the layer of silicon nitride.
4. The process of claim 1 , wherein the step of oxidizing one or more of the silicon dioxide and the silicon nitride occurs at a top surface of the insulating layer.
5. The process of claim 1 , wherein the step of oxidizing one or more of the silicon dioxide and the silicon nitride forms a deactivated oxidized silicon dioxide or a deactivated oxidized silicon nitride.
6. The process of claim 1 , wherein a plurality of insulating layers is applied to the substrate.
7. The process of claim 1 , wherein the aperture is etched through the insulating layer.
8. The process of claim 1 , wherein allowing one or more of the oxidized silicon dioxide and the oxidized silicon nitride to react with the functionalized silane includes applying a vacuum.
9. The process of claim 1 , wherein the self-assembled monolayer of a functionalized silane provides a hydrophobic coating.
10. A process for the manufacture of a biosensing device, the process comprising:
providing a substrate having an electrically conductive lead on a surface thereof;
applying an insulating layer to the substrate and the electrically conductive lead, said insulating layer comprising one or more of silicon dioxide and silicon nitride;
etching an aperture in the insulating layer to expose a portion of the electrically conductive lead onto which a nanostructured microelectrode is to be plated;
etching a surface of the insulating layer and a surface of the electrically conductive lead to clean and/or oxidize the surfaces; and
capping the etched surface of the insulating layer with a self-assembled monolayer of functionalized silane.
11. The process of claim 10 , wherein a plurality of insulating layers is applied to the substrate.
12. The process of claim 11 , wherein the aperture is etched through an insulating layer.
13. The process of claim 10 , wherein etching the surface comprises subjecting the surface to plasma etching.
14. The process of claim 10 , wherein the functionalized silane is a trichlorosilane.
15. The process of claim 14 , wherein the trichlorosilane has a functionalized alkyl side chain.
16. The process of claim 15 , wherein the trichlorosilane is trichloro(1H, 1H, 2H, 2H-perfluorooctyl) silane or trichlorododecylsilane.
17. The process of claim 10 , wherein oxidizing the surface occurs during exposure to oxygen plasma.
18. The process of claim 10 , further comprising: plating the nanostructured microelectrode in the aperture.
19. The process of claim 10 , wherein capping the etched surface of the insulating layer with the self-assembled monolayer of functionalized silane includes reacting the functionalized silane under a vacuum with an oxidized surface of the insulating layer.
20. The process of claim 10 , wherein the self-assembled monolayer of a functionalized silane provides a hydrophobic coating.