Nanoparticulate chemical sensors using SERS
A system to selectively deliver relatively small analyte molecules of interest to a SERS-active nanoparticle surface while excluding dozens to hundreds of other species in the environment. In particular, the present invention provides a permselective film that renders the particles of interest as viable small molecule optically addressable sensors.
1. A composition of matter comprising:
a particle having a spectroscopy-active outer region; and
a permselective film associated with at least a portion of the particle which selectively allows for specific molecules to reach the outer region of the particle and produce a spectrum when illuminated.
2. The composition of matter of claim 1 , wherein the particle comprises a metal.
3. The composition of matter of claim 2 , wherein said metal is selected from the group consisting of Au, Ag, Cu, Na, K, Cr, AI, and Li.
4. The composition of matter of claim 1 wherein the permselective film is selected from the group consisting of a globular polymer, a hyperbranched polymer, polydimethylsiloxane, and a porous glass film.
5. The composition of matter of claim 1 wherein the particle is a metal nanoparticle.
6. The composition of matter of claim 5 , wherein said metal nanoparticle has a diameter less than about 200 nm.
7. The composition of matter of claim 6 , wherein said metal nanoparticle has a diameter between about 20 nm and about 200 nm.
8. The composition of matter of claim 7 , wherein said metal nanoparticle has a diameter between about 40 nm and about 100 nm.
9. The composition of matter of claim 1 , wherein said permselective film has a thickness of about 10 nm.
10. The composition of matter of claim 1 , wherein said permselective film has a thickness less than 10 nm.