Jp. Barnes et Jh. Freed, AQUEOUS SAMPLE HOLDERS FOR HIGH-FREQUENCY ELECTRON-SPIN-RESONANCE, Review of scientific instruments, 68(7), 1997, pp. 2838-2846
A quasioptical approach is utilized to design a resonator and sample h
older for aqueous samples for high-frequency (250 GHz) electron spin r
esonance (ESR) spectroscopy. A disk shaped sample geometry was chosen
to match the field contours of the fundamental mode in a Fabry-Perot r
esonator. A transmission-line analysis is used to determine the optimu
m sample geometry while taking into account diffractive effects of the
sample and the sample holder on the far infrared (FIR) radiation fiel
d. FIR-ESR spectra of several aqueous solutions of nitroxide spin labe
ls, including membrane vesicles and a labeled protein, are shown to de
monstrate the success of the technique. (C) 1997 American Institute of
Physics.