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Rapid Sequencing of Individual DNA Molecules in Graphene Nanogaps

Henk Postma


Materials with intrinsic nanometer-scale dimensions show tremendous potential for nanoelectronics and sensing applications. First, ultraminiaturized mass spectrometers are highly sought-after tools, with numerous applications in areas such as environmental protection, exploration, and drug development. We realize atomic scale mass sensing using doubly clamped suspended carbon nanotube nanomechanical resonators, in which their single-electron transistor properties allows self-detection of the nanotube vibration [1]. Second, I discuss our progress in demonstrating how a nanogap in a graphene sheet may be used for rapid single-molecule DNA sequencing. Graphene is an ideal material for DNA sequencing due to its single-atom thickness that allows for single-base interrogation of the DNA’s transverse conductance. The estimated error rate is 0% up to a gap width of 1.6 nm [2].

[1] Atomic-Scale Mass Sensing Using Carbon Nanotube Resonators, H.-Y. Chiu., P. Hung., H.W.Ch. Postma. and M. Bockrath, Nano Letters 8, 4342 (2008) [2] Rapid Sequencing of Individual DNA Molecules in Graphene Nanogaps, H.W.Ch. Postma, Nano Letters 10, 420 (2010)


Henk Postma is an Assistant Professor at California State University Northridge in the Department of Physics and Astronomy. He received his PhD at Delft University of Technology in Dec 2001, working with Prof. Cees Dekker on carbon nanotube junctions and devices. Afterwards, he became a postdoctoral scholar at Caltech in the group of Prof. Michael Roukes, studying dynamic range and basins of attraction of high frequency platinum nanowire NEMS resonators. He then became a senior postdoctoral scholar in the group of Prof. Marc Bockrath at Caltech, studying single-atom mass detection in carbon nanotube resonators, self assembly of nano circuits, ballistic phonon transport and nanorelays. His current interests are in the properties of materials with intrinsic nanoscale dimensions, such as carbon nanotubes, graphene, nanowires, and DNA. Their small dimensions give rise to interesting effects, such as quantum confinement, and we utilize these for novel applications in computation, sensing, and information storage.

Henk Postma Headshot
Henk Postma
Cal State Northridge
EEB 105
18 Jan 2011, 12:00am until 11:30am