Characterization and application of vertical nanopillar-based sensors for probing cellular functions

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Abstract/Contents

Abstract
Vertically aligned nanopillars can serve as excellent electrical, optical and mechanical platforms for biological studies. To date, the interface between cells and nanopillars, particularly the conformation of the cell membrane and nucleus, has not been well characterized despite its importance to the choice of feasible applications for nanopillar substrates to cellular studies. We characterized the cell-nanopillar interface by fluorescence, scanning electron and transmission electron microscopy on nanopillars with a range of diameters, pitch and heights. We found that the cell membrane wraps around the entirety of the nanopillar without loss of membrane integrity, contrary to prior suggestions. We also observed that the membrane-surface gap of both cell bodies and neurites is smaller for nanopillars than for a flat substrate. These results support a tight interaction between the cell membrane and the nanopillars and previous findings of excellent sealing in electrophysiology recordings using nanopillar electrodes. Subsequently, we took advantage of the cell-nanopillar interface to develop applications of nanopillar arrays to mechanical and optical measurements in living cells. We observed that vertical nanopillar arrays significantly deform the nuclear envelope, and the extent of deformation is sensitive to both the stiffness of the nucleus and the stiffness of the cytoskeleton. Thus, nanopillar arrays constitute a novel approach for non-invasive, subcellular perturbation of nuclear mechanics and open up exciting new possibilities for the study of nuclear mechanotransduction in live cells. In addition to serving as mechanical probes, we developed a nanopillar-based platform for single molecule measurements in live cells. With a diameter much smaller than the wavelength of visible light, a transparent silicon dioxide nanopillar embedded in a nontransparent substrate restricts the propagation of light and affords evanescence wave excitation along its vertical surface. We showed that nanopillar illumination can be used for in vitro single molecule detection with high background. In addition, the tight interface between vertical nanopillars and live cells allows them to function as highly localized light sources inside the cell. Overall, nanopillar arrays are a powerful platform for studying cell function through electrical, optical and mechanical measurements.

Description

Type of resource text
Form electronic; electronic resource; remote
Extent 1 online resource.
Publication date 2014
Issuance monographic
Language English

Creators/Contributors

Associated with Hanson, Lindsey
Associated with Stanford University, Department of Chemistry.
Primary advisor Cui, Bianxiao
Thesis advisor Cui, Bianxiao
Thesis advisor Cui, Yi, 1976-
Thesis advisor Dai, Hongjie, 1966-
Advisor Cui, Yi, 1976-
Advisor Dai, Hongjie, 1966-

Subjects

Genre Theses

Bibliographic information

Statement of responsibility Lindsey Hanson.
Note Submitted to the Department of Chemistry.
Thesis Thesis (Ph.D.)--Stanford University, 2014.
Location electronic resource

Access conditions

Copyright
© 2014 by Lindsey Hanson
License
This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).

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