Biomolecules and nanostructures
The Optical Sciences group studies the interaction of light and matter. Our current focus is on detection and sensing/imaging with an emphasis on the development of integrated photonics. We are part of Twente University's Department of Science and Technology and member of the MESA+ institute.
Genetic applications of single molecular detection
Combined near-field fluorescence and shear force microscopy is applied to image and study genetic material with single molecular cytochemical sensitivity. The combination brings together several advantages: (I) resolution beyond the diffraction limit, while retaining the advantages of multi-colour detection and single molecule sensitivity; (II) complemented with molecular resolution topographical imaging, using shear force feedback, for unambiguous localisation of fluorophores. Thus mapping and co-localisation studies of genetic material are performed at an individual molecular level. The location of maximum fluorescence of the molecule is determined with an accuracy of ~ 1 nm. The in-plane orientation of the molecular dipole is readily determined for all molecules in a single image using polarisation excitation/detection. With the same probe shear force phase feedback is used for topographic imaging of DNA complexes, with 0.2 nm vertical sensitivity. Dynamic environmental effects on nucleotide photophysics will be investigated on single molecular basis.
The following articles have been published regarding this project:
Near-field optical microscopy for DNA studies at the single molecular level(abstract) (full pdf)
Garcia-Parajo MF, Veerman JA, van Noort SJT, de Grooth BG, Greve J, van Hulst NF
vol 6 issue 1: p43-p53 MAR 1998
Near-field optical and shear-force microscopy of single fluorophores and DNA molecules(abstract) (full pdf)
Garcia-Parajo MF, Veerman JA, Ruiter AGT, van Hulst NF
vol 71 issue 1-4: p311-p319 MAR 1998
Near-field fluorescence imaging of genetic material: Toward the molecular limit(abstract)
vanHulst NF, GarciaParajo MF, Moers MHP, Veerman JA, Ruiter AGT
JOURNAL OF STRUCTURAL BIOLOGY
vol 119 issue 2: p222-p231 1997