Enhanced imaging of biomolecules with electron beam deposited tips for scanning force microscopy
- 1 June 1993
- journal article
- Published by AIP Publishing in Journal of Applied Physics
- Vol. 73 (11), 7232-7237
- https://doi.org/10.1063/1.354010
Abstract
Tip/sample interaction on the scanning force microscope (SFM) is a particularly difficult problem with biological materials. One major factor affecting image quality is the tip shape. Improved electron beam induced deposition technique with a scanning electron microscope (SEM) was used for the reproducible fabrication of carbon sharp tips on the end of commercially available silicon nitride cantilevers for scanning force microscopy. By aligning a fine focused beam of 20 nm diameter directly down the axis of the pyramidal tip at electron energy of 20 kV, carbon deposits grow with full cone angle of about 25°, cone length of 2 μm, and radii of curvature down to 10 nm, making these e-beam tips suitable for biomolecules imaging. The tip dimensions also were controlled by adjusting the beam parameters. Three different types of SFM tips were used to image tobacco mosaic virus (TMV). Conventional pyramidal tips appeared generally worse for imaging helical particles of TMV than SEM-deposited tips which were found more robust than commercially available conical tips. The use of sharper tips for SFM imaging of protein DNA revealed a 25% improvement in lateral resolution.Keywords
This publication has 19 references indexed in Scilit:
- Scanning force microscopy and cryo-electron microscopy of tobacco mosaic virus as a test specimenUltramicroscopy, 1992
- Substrate preparation for reliable imaging of DNA molecules with the scanning force microscopeUltramicroscopy, 1992
- Reproducible Imaging and Dissection of Plasmid DNA Under Liquid with the Atomic Force MicroscopeScience, 1992
- Imaging of DNA by scanning force microscopyJournal of Structural Biology, 1992
- DNA and RNA polymerase/DNA complex imaged by scanning force microscopy: Influence of molecular‐scale frictionScanning, 1992
- Micromachined silicon sensors for scanning force microscopyJournal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 1991
- Atomic scale friction between the muscovite mica cleavage plane and a tungsten tipThe Journal of Chemical Physics, 1988
- Atomic resolution with the atomic force microscope on conductors and nonconductorsJournal of Vacuum Science & Technology A, 1988
- Atomic-scale friction of a tungsten tip on a graphite surfacePhysical Review Letters, 1987
- Atomic resolution imaging of a nonconductor by atomic force microscopyJournal of Applied Physics, 1987