Researchers Reach Femtogram-Level Chemical Characterization

Champaign, IL (Mar. 27)-Combining atomic force microscopy and infrared spectroscopy, scientists at the University of Illinois have demonstrated a method for simultaneous structural and chemical characterization of samples at the femtogram (10^-15g) level.

Their technique is based on a silicon cantilever probe in an atomic force microscope. The probe integrates a heater-thermometer that is controlled in the 25–1000 °C temperature range, which allows extraction of very small samples of material for imaging. To analyze a sample, the heater temperature is raised to slightly above the melting point of the sample material. The material is then analyzed by Raman or Fourier transform infrared (FTIR) spectroscopic imaging.

“We anticipate this approach will help bridge the gap between nanoscale structural analysis and conventional molecular spectroscopy in a manner widely useful to most analytical laboratories,” said William P. King, professor of mechanical science and engineering at the University of Illinois.