Ultrasensitive magnetic resonance by mechanical detection

COLL 403

Seppe Kuehn, sk288@cornell.edu1, Steven A. Hickman1, Roger F. Loring2, and John A. Marohn, jam99@cornell.edu1. (1) Department of Chemistry and Chemical Biology, Cornell University, 150 Baker Laboratory, Ithaca, NY 14853, (2) Department of Chemistry and Chemical Biology, Cornell University, Baker Laboratory, Ithaca, NY 14853-1301
Magnetic resonance force microscopy (MRFM) is a three-dimensional, subsurface imaging technique which detects sample spins via the deflection, or change in mechanical resonance frequency, of a magnet-tipped cantilever. MRFM combines the superior sensitivity of scanned probe microscopies with the chemical specificity of NMR. At single-nuclear-spin sensitivity, MRFM would have exciting biomedical applications, such as structure determination of single proteins. We have previously reported unprecedented sensitivity in nuclear MRFM, and are improving the sensitivity of our measurements by attacking two remaining challenges. We have explored the dominant source of noise in our measurement: non-contact friction between the magnetic tip and the sample. We have demonstrated, at room temperature that this non-contact friction can result from dielectric fluctuations within the sample. We are exploiting electron beam lithography to reduce the size of our magnetic tips from ten micrometers to 50 nanometers. Using these new tips, we project a sensitivity of 1000 protons.
 

Advances in Nanomedicine
8:30 AM-12:00 PM, Tuesday, 12 September 2006 Sir Francis Drake -- Monterey/Cypress Rooms, Oral

Division of Colloid & Surface Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006