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Biological specimen preparation; Biological techniques and instruments; Leakage currents; Scanning tunnelling microscopy; Biophysical instrumentation and techniques [A8780]; Electron microscopy determinations of structures [A6116D]
Abstract:
For scanning tunneling microscopy of biological samples a thin, sharp tip is necessary to resolve the highly corrugated structures of biomacromolecules. By DC etching of tungsten wire in NaOH the authors obtain tip radii of 5 nm or less in more than 50% of all cases. For tunneling in fluids these tips are insulated by a wax-coating to minimize faradaic currents. Resulting leakage currents are in the range of 5 to 50 pA. (6 References).
