Currently, measuring the levels of certain chemicals within the brain requires that a hole be drilled through the skull. In search of a less dramatic method of studying the brain’s workings, a team of researchers have shown that Raman spectroscopy can be used to detect chemicals through the bone. They proved their concept by injecting a cut of lamb meat with chemically modified gold nanoparticles treated to have a strong Raman signature, and then shone the laser on the bone on the opposite side of the injection. The team was immediately able to detect the chemical signature of the altered molecules.

The technology is exciting, but is still just a first step toward using Raman as a brain imaging technique. However, as Richard P. Van Duyne (whose team used the technique to monitor glucose levels through the skin of live rats, “This is just step one, but it’s a showstopper.”