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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 17: Micro and Nano Fluidics I: Structured Substrates

CPP 17.6: Vortrag

Mittwoch, 28. März 2007, 15:30–15:45, H37

Nanobubbles in Solid-State Nanopores — •U. F. Keyser^1,2, R. M. M. Smeets¹, M. Y. Wu¹, N. H. Dekker¹, and C. Dekker¹ — ¹Kavli Institute of Nanoscience, Delft University of Technology, The Netherlands — ²Institut für Experimentelle Physik I, Universität Leipzig, Germany

From conductance and noise studies, we infer that nanometer-sized gaseous bubbles (nanobubbles) are the dominant noise source in solid-state nanopores[1]. We study the ionic conductance through solid-state nanopores as they are moved through the focus of an infrared laser beam. The resulting conductance profiles show strong variations in both the magnitude of the conductance and in the low-frequency noise when a single nanopore is measured multiple times. Differences up to 5 orders of magnitude are found in the current power spectral density. In addition, we measure an unexpected double-peak ionic conductance profile. A simple model of a cylindrical nanopore that contains a nanobubble explains the measured profile and accounts for the observed variations in the magnitude of the conductance.

[1] R. M. M. Smeets, U. F. Keyser et al., Phys. Rev. Lett. 97, 088101 (2006)