Nanoscale depth resolution in scanning near-field infrared microscopy.

We have recorded nanoscale topography and infrared chemical fingerprints of attomole layered lipids consisting of dimyristoylpho-sphatidylcholine on silicon and mica. Lipids deposited on mica built stacks consisting of up to 25 bilayers, each approximately 5 nm thick, spanning a range from 5-125 nm in height. Contrast evaluation as a function of layer thickness provides the near-field depth resolution.