Surface enhanced spectroscopy-active composite nanoparticles
View Patent ↗Metal nanoparticles associated with a spectroscopy-active (e.g., Raman-active) analyte and surrounded by an encapsulant are useful as sensitive optical tags detectable by surface-enhanced spectroscopy (e.g., surface-enhanced Raman spectroscopy).
1. A particle comprising: a surface-enhanced spectroscopy (SES) active metal nanoparticle, a SES active label associated with said SES-active metal nanoparticle, and an encapsulant for reducing aggregation surrounding said SES-active metal nanoparticle and said SES-active label, wherein said encapsulant comprises a material selected from the group consisting of glass, polymers, metal oxides, and metal sulfides, and wherein said particle has a measurable SES spectrum.
2. The particle of claim 1 , wherein said metal nanoparticle comprises a metal selected from the group consisting of Au, Ag, Cu, Na, Al, and Cr.
3. The particle of claim 2 , wherein said metal nanoparticle comprises Au.
4. The particle of claim 2 , wherein said metal nanoparticle comprises Ag.
5. The particle of claim 1 wherein said metal nanoparticle comprises an alloy of metals selected from the group consisting of Au, Ag, Cu, Na, Al, and Cr.
6. The particle of claim 1 , wherein said metal nanoparticle has a diameter less than about 200 nm.
7. The particle of claim 6 , wherein said metal nanoparticle has a diameter between about 20 nm and about 200 nm.
8. The particle of claim 7 , wherein said metal nanoparticle has a diameter between about 40 nm and about 100 nm.
9. The particle of claim 1 , wherein said metal nanoparticle is a sphere.
10. The particle of claim 1 , wherein said metal nanoparticle is an oblate sphereoid.
11. The particle of claim 1 , wherein said metal nanoparticle is a prolate spheroid.
12. The particle of claim 1 , wherein said encapsulant has a thickness less than about 1 micron.
13. The particle of claim 12 , wherein said encapsulant has a thickness between about 1 nm and about 40 nm.
14. The particle of claim 13 , wherein said encapsulant has a thickness between about 5 nm and about 15 nm.
15. The particle of claim 1 , wherein said encapsulant comprises a plurality of materials.
16. The particle of claim 1 , wherein said encapsulant comprises glass (SiO x ).
17. The particle of claim 1 , wherein said encapsulant comprises TiO 2 .
18. The particle of claim 1 , wherein said spectroscopy-active label forms a partial monolayer coating on said metal nanoparticle.
19. The particle of claim 1 , wherein said spectroscopy-active label forms a monolayer coating on said metal nanoparticle.
20. The particle of claim 1 , wherein said spectroscopy-active label forms a multilayer coating on said metal nanoparticle.
21. The particle of claim 1 , wherein said measurable SES spectrum is a spectrum obtained by a method selected from the group consisting of surface-enhanced Raman spectroscopy, surface-enhanced resonance Raman spectroscopy, surface-enhanced hyperRaman spectroscopy, surface-enhanced resonance hyperRaman spectroscopy, and surface-enhanced infared spectroscopy.
22. The particle of claim 1 , wherein said spectroscopy-active analyte is an aromatic analyte.
23. A particle comprising a gold nanoparticle having a diameter of between about 20 nm and about 100 nm, a surface-enhanced spectroscopy (SES)-active label associated with said gold nanoparticle, and glass having a thickness of between about 1 nm and about 15 nm surrounding said gold nanoparticle and said SES-active label, wherein said SES-active label has a measurable SES spectrum.
24. The particle of claim 23 wherein said measurable SES spectrum is a spectrum obtained by a method selected from the group consisting of surface-enhanced Raman spectroscopy, surface-enhanced resonance Raman spectroscopy, surface-enhanced hyperRaman spectroscopy, surface-enhanced resonance hyperRaman spectroscopy, and surface-enhanced infared spectroscopy.
25. A particle comprising a surface-enhanced spectroscopy (SES) active metal nanoparticle, an aromatic label adsorbed on the surface of said (SES) active metal nanoparticle, and an encapsulant for reducing aggregation surrounding said (SES) active metal nanoparticle and said aromatic label, wherein said encapsulant comprises a material selected from the group consisting of glass, polymers, metal oxides, and metal sulfides.
26. The particle of claim 25 , wherein said metal nanoparticle comprises a metal selected from the group consisting of Au, Ag, Cu, Na, Al, and Cr.
27. The particle of claim 25 , wherein said metal nanoparticle has a diameter less than about 200 nm.
28. The particle of claim 27 , wherein said metal nanoparticle has a diameter of between about 20 nm and about 200 nm.
29. The particle of claim 28 , wherein said metal nanoparticle has a diameter of between about 40 nm and about 100 nm.
30. The particle of claim 25 wherein said encapsulant has a thickness less than about 1 micron.
31. The particle of claim 30 wherein said encapsulant has a thickness of about 1 nm and about 40 nm.
32. The particle of claim 31 wherein said encapsulant has a thickness of between about 5 nm and about 15 nm.