Finally, a use for carbon monoxide!

Via my friend Don Weber*, via Slashdot, via Science (the journal, and, I suppose, thence via science, the epistemological pursuit), comes a report from IBM Zurich on imaging single surface adsorbed molecules at the atomic level** using an AFM tip functionalized with carbon monoxide atoms. Imaging single adsorbed molecules, not in a lattice context, is very difficult. In this case, they were directly imaging Pauli repulsion, which is pretty neat. It's interesting to think, sometimes, that the fact that your coffee cup doesn't pass through the table is basically just the Pauli exclusion force at work. And here it is, again, writ very small. I don't know what the implications for biology are, since interesting biological molecules are generally not planar. But interesting work nonetheless. c.f. this work on imaging single spins using an AFM.



*Before I went to grad school, Don and I worked at a now defunct software company together in Chicago called Geodesic Systems, and shared an office with two other people. I once gave a lunchtime talk on biophysics, back when I had never given any talks and didn't really know how to give a decent talk, and Don fell asleep in the middle of the talk. His comment upon mailing this to me was, "I didn't even fall asleep while reading it!"

**More memories: We did an AFM lab when I was an undergrad, with a "teaching" AFM, trying to image a HOPG lattice. The AFM was suspended from the ceiling using bungee cords as a method of noise dampening. Unfortunately, in the other half of the lab, people were trying to do Compton scattering, which involved moving lead bricks around. We would sit, holding our breath, as line after line of the image would form, and then somebody on the other end of the lab would drop a lead brick on the ground: BANG! And the image would do the optical equivalent of a phonograph needle squealing on a record. Fun times, fun times.