Medical device and method for diagnostic sensing

1. A method of detecting an analyte in vivo comprising:

implanting at a site in a patient a device which comprises:

one or more discrete reservoirs each containing at least one reacting component,

at least one non-degradable barrier layer covering an opening in each of the one or more discrete reservoirs, the non-degradable barrier layer being selectively permeable to an analyte to be detected, wherein the reacting component remains inside the reservoirs, and

a degradable barrier layer, which is impermeable to the analyte to be detected and which covers the at least one non-degradable barrier layer over the reservoir opening;

disintegrating or permeabilizing the degradable barrier layer over at least one of the reservoirs to permit the analyte at the site to enter the reservoir and react with the at least one reacting component; and

using a sensor positioned externally from the reservoir to detect the reaction between the reacting component and the analyte.

2. The method of claim 1 , wherein the detecting comprises imaging or optical detection.

3. The method of claim 1 , wherein the at least one non-degradable barrier layer comprises a semi-permeable polymeric membrane.

4. The method of claim 1 , wherein the at least one non-degradable barrier layer comprises a nanoporous or microporous silicon membrane.

5. The method of claim 1 , wherein the non-degradable barrier layer is in the form of a plurality of discrete reservoir caps.

6. The method of claim 1 , wherein the degradable barrier layer comprises a biodegradable polymeric material.

7. The method of claim 1 , wherein the degradable barrier layer comprises a metal film and the device further includes a power source and control circuitry for disintegrating the degradable barrier layer.

8. The method of claim 1 , wherein the reaction between the reacting component and the analyte to be detected is a binding reaction.

9. A method of detecting an analyte in vivo comprising:

implanting at a site in a patient a device which comprises:

a plurality of discrete reservoirs located in a substrate, each reservoir having at least one opening,

at least one reacting component contained in each reservoir,

at least one non-degradable barrier layer, which is permeable to an analyte to be detected and covers each reservoir opening, wherein the reacting component remains inside the reservoirs, and

a degradable barrier layer, which is impermeable to the analyte to be detected and which covers the at least one non-degradable barrier layer over the reservoir opening; and

disintegrating or permeabilizing the at least one degradable barrier layer to permit the analyte at the site to enter the reservoirs and undergo a binding reaction with the at least one reacting component; and

using a sensor positioned externally from the reservoir to detect the binding reaction between the reacting component and the analyte.

10. The method of claim 9 , wherein the substrate comprises a polymer.

11. The method of claim 9 , wherein the at least one degradable barrier layer comprises a biodegradable polymeric material.

12. The method of claim 9 , wherein the at least one degradable barrier layer comprises a metal film and the device further includes a power source and control circuitry for disintegrating the degradable barrier layer.

13. The method of claim 9 , wherein the at least one non-degradable barrier layer comprises a semi-permeable polymeric membrane.

14. The method of claim 9 , wherein the at least one non-degradable barrier layer comprises a nanoporous or microporous silicon membrane.

15. A method of detecting an analyte in vivo comprising:

implanting in a patient a device which comprises:

a plurality of discrete reservoirs located in a substrate, each reservoir having at least one opening,

at least one non-degradable barrier layer which comprises a semi-permeable polymeric membrane, which is permeable to an analyte to be detected and which covers each reservoir opening,

a degradable barrier layer, which is impermeable to the analyte to be detected and which covers the at least one non-degradable barrier layer over the reservoir opening, and

at least one reacting component which remains contained inside each of the reservoirs and can undergo a binding reaction with the analyte,

passively or actively degrading the at least one degradable barrier layer to permit the analyte to enter the reservoirs and react with the at least one reacting component; and

using a sensor positioned externally from the reservoir to detect the reaction between the reacting component and the analyte.

16. The method of claim 15 , wherein the degradable barrier layer comprises a biodegradable polymeric material.

17. The method of claim 15 , wherein the degradable barrier layer comprises a metal film and the device further includes a power source and control circuitry for disintegrating the degradable barrier layer.

18. The method of claim 15 , wherein the substrate comprises a polymer.

19. The method of claim 15 , wherein the step of detecting comprises imaging or optical detection.

20. The method of claim 1 , wherein the reacting component is selected from the group consisting of metals, proteins, nucleic acids, cells, and combinations thereof.

21. The method of claim 9 , wherein the reacting component is selected from the group consisting of metals, proteins, nucleic acids, cells, and combinations thereof.

22. The method of claim 15 , wherein the reacting component is selected from the group consisting of metals, proteins, nucleic acids, cells, and combinations thereof.