Analyte detection system and method for intradermal implantation of biocompatible optode nanosensors

1. A device comprising:

a plurality of micro-needles, each having a base end and a tip;

a planar optically transparent substrate directly attached to the base ends of the micro-needles, wherein the substrate can attach to an external skin surface such that the micro-needles penetrate into the skin;

nanoparticles associated with the micro-needles, the nanoparticles having an optically detectable label for interacting with a target analyte present in interstitial fluid; and

water-soluble adhesive material for attaching the base ends of the micro-needles to the substrate.

2. The device of claim 1 , wherein the adhesive material is located on the substrate for attaching the substrate to the external skin surface and for attaching the base ends of the micro-needles to the substrate.

3. The device of claim 2 , wherein the adhesive is water-soluble such that the substrate can be detached from the base end of the micro-needles and from the external skin surface in the presence of water.

4. The device of claim 1 , wherein the micro-needles are arranged in a three dimensional spatially-controlled array.

5. The device of claim 1 , wherein the micro-needles are solid, hollow or porous.

6. The device of claim 1 , wherein the nanoparticles are bound to a surface of the micro-needles.

7. The device of claim 1 , wherein the nanoparticles are encapsulated in the micro-needles.

8. The device of claim 1 , wherein the micro-needles comprise hollow or porous spaces comprising the nanoparticles.

9. The device of claim 1 , wherein the micro-needles, the nanoparticles, or both are biodegradable.

10. The device of claim 1 , wherein the micro-needles are non-dissolvable and are coated with a dissolvable coating of a polymer and the nanoparticles.

11. A system comprising:

(a) a skin-mountable device, comprising:

a plurality of micro-needles, each having a base end and a tip;

a planar optically transparent substrate directly attached to the base ends of the micro-needles, wherein the substrate can attach to an external skin surface such that the micro-needles penetrate into the skin; and

nanoparticles associated with the micro-needles, the nanoparticles having an optically detectable label for interacting with a specific target analyte present in interstitial fluid;

water-soluble adhesive material for attaching the base ends of the micro-needles to the substrate; and

(b) a reader device, wherein the target analyte can be detected by the reader device via interaction with the skin-mountable device.

12. The system of claim 11 , wherein the detectable label comprises a fluorophore.

13. The system of claim 12 , wherein the target analyte can be detected by the reader device by optically interrogating the nanoparticles in the skin-mountable device.

14. The system of claim 13 , wherein the reader device comprises:

a light source; and

a photodetector, wherein light is directed toward the substrate by the light source and wherein light from the substrate is detected by the photodetector.

15. The system of claim 14 , wherein an optically-detectable change related to the nanoparticles interacting with the target analyte is detected by the reader device.

16. The system of claim 15 , wherein the optically-detectable change comprises a change in at least one of optical absorption, reflectivity, or fluorescence.

17. The system of claim 16 , wherein the optically-detectable change is fluorescence.

18. The system of claim 11 , wherein the skin-mountable device further comprises an antenna, and wherein the target analyte is detected by the reader device based on data communicated via the antenna.

19. The system of claim 18 , wherein the data communicated via the antenna is indicative of one or more measurements obtained by the skin-mountable device.

20. The system of claim 11 , wherein the reader device is a wearable device.

21. A method, comprising:

mounting a skin-mountable device to a skin surface, wherein the skin-mountable device comprises (i) a plurality of micro-needles, each having a base end and a tip, (ii) a planar optically transparent substrate directly attached to the base ends of the micro-needles, wherein the substrate can attach to an external skin surface such that the micro-needles penetrate into the skin, (iii) nanoparticles associated with the micro-needles, the nanoparticles having a fluorophore for interacting with a target analyte present in interstitial fluid, and (iv) water-soluble adhesive material for attaching the base ends of the micro-needles to the substrate;

transmitting incident light from a reader device to the skin-mountable device;

receiving, by the reader device, fluorescence light emitted by the nanoparticles interacting with the target analyte in response to the incident light;

detecting the target analyte based on the fluorescence light received by the reader; and

removing the planar optically transparent substrate from the skin surface and from the micro-needles.

22. The method of claim 21 , wherein detecting the target analyte based on the fluorescence light received by the reader comprises determining a concentration of the target analyte in the interstitial fluid based on the fluorescence light received by the reader.

23. The method of claim 21 , wherein the substrate comprises a polymeric material transparent to the incident light and the fluorescence light.

24. The method of claim 21 , wherein the target analyte is Na + , K + , Ca 2+ , glucose, urea, creatinine, bicarbonate, or chloride.