Scanning tunneling microscopy of insulators and biological specimens based on lateral conductivity of ultrathin water films
- 2 December 1994
- journal article
- Published by American Association for the Advancement of Science (AAAS) in Science
- Vol. 266 (5190) , 1538-1540
- https://doi.org/10.1126/science.7985024
Abstract
Scanning tunneling microscopy is based on the flow of an electrical current and thus cannot be used to directly image insulating material. It has been found, however, that a very thin film of water (about one monolayer) adsorbed to a surface exhibits a surprisingly high conductivity that is sufficient to allow scanning tunneling microscope imaging at currents below 1 picoampere. Hydrophilic insulators, such as glass and mica, can thus be imaged in humid air. The same is true for biological specimens deposited on such surfaces, as demonstrated by the scanning tunneling microscope imaging of plasmid DNA on mica.Keywords
This publication has 10 references indexed in Scilit:
- Imaging of uncoated tobacco mosaic virus by scanning tunneling microscopyJournal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 1994
- Studies of covalently immobilized protein molecules by scanning tunneling microscopy: the role of water in image contrast formationThe Journal of Physical Chemistry, 1993
- Scanning force microscopy of circular and linear plasmid DNA spread on mica with a quaternary ammonium saltNucleic Acids Research, 1993
- Preparation and characterization of tips for scanning tunneling microscopy of biological specimensUltramicroscopy, 1992
- Hydration force microscopy as a new option for studies of solid—liquid interfaces: Some theoretical considerationsJournal of Electroanalytical Chemistry, 1992
- Alternative method of imaging surface topologies of nonconducting bulk specimens by scanning tunneling microscopyPhysical Review Letters, 1991
- Inadequacy of Lifshitz theory for thin liquid filmsPhysical Review Letters, 1991
- Thickness determination of biological samples with a zeta-calibrated scanning tunneling microscope.Proceedings of the National Academy of Sciences, 1990
- Scanning tunneling microscopy of a hydrated bacterial surface proteinUltramicroscopy, 1989
- A scanning tunneling microscope (STM) for biological applications: design and performanceUltramicroscopy, 1988