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Optical Sciences
P.O. Box 217
7500 AE Enschede
The Netherlands
E-mail:
Phone: +31 53 489 3805
Fax: +31 53 489 3511
| Home |
| Research |
| Members |
| Publications |
| Vacancies |
| Intra |
| Route/Contact |
Optical Sciences
P.O. Box 217
7500 AE Enschede
The Netherlands
E-mail:
Phone: +31 53 489 3805
Fax: +31 53 489 3511
MicroCOR
perspect-H20
Biomolecules and nanostructuresThe Optical Sciences group studies the interaction of light and matter at the nanoscale.
We do this by exploring ways to shape light and its environment. It's what we call
active and passive control. Our current focus is on the interaction of light with
biomolecules and nanostructures. We are part of Twente
University's Department of Science and Technology and member of the
MESA+ institute. |
|
Near-field optical microscopy for DNA studies at the single molecular level(full pdf)Garcia-Parajo MF, Veerman JA, van Noort SJT, de Grooth BG, Greve J, van Hulst NF BIOIMAGING vol 6 issue 1: p43-p53 MAR 1998 An aperture-type near-field optical microscope (NSOM) with two polarization detection channels has been used to image fluorescently labelled DNA with high spatial resolution and single molecule fluorescence sensitivity. The sample has been engineered such that there is only one rhodamine dye per DNA strand. Lateral and vertical DNA dimensions in the shear-force image are 14 +/- 2 nm and 1.4 +/- 0.2 nm, respectively. No sample deformation was observed under our imaging conditions. Near-field fluorescence imaging of individual fluorophores shows an optical resolution of 70 nm at full-width at half- maximum. Large intensity differences between individual rhodamine molecules attached to DNA are observed from the NSOM images. Statistics on rhodamine dyes in different environments (attached to glass, embedded in a polymer layer and attached to DNA) show bleaching rates of 10(-5). Total intensity line profiles together with in-plane angle orientation are used to characterize individual dyes. Rhodamine dyes show strong intensity fluctuations independent of the particular environment. These results are in contrast with the more stable photophysical behaviour as observed for carbocyanine molecules embedded in polymer matrices. The mobility of rhodamine-both lateral and rotational-is clearly influenced by its immediate surrounding and attachment to the surface. |
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