Send to

Choose Destination
See comment in PubMed Commons below
Nano Lett. 2009 Feb;9(2):903-8. doi: 10.1021/nl803903f.

Background suppression in near-field optical imaging.

Author information

Institute of Optics, University of Rochester, Rochester, New York 14627, USA.


In several recent studies, antenna-based optical microscopy has demonstrated its potential to resolve features as small as 10 nm. Most studies are concerned with well-separated features on flat surfaces, and there are only few studies that deal with samples of high feature density or even three-dimensional objects. The reason is that the external laser irradiation of the optical antenna (e.g., tip or particle) also directly irradiates the sample and therefore gives rise to a background. Here we introduce an efficient background suppression scheme that makes use of feedback modulation. The method is widely applicable and not restricted to cantilever-based scanning schemes. We apply this technique to both dense samples of dye molecules and ion channel proteins in plasma membranes and demonstrate effective background suppression and strongly improved sensitivity. The feedback modulation scheme is expected to find application for biological studies in liquid environments and for investigations of subsurface features in material science.

[Indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for American Chemical Society Icon for PubMed Central
    Loading ...
    Support Center