Nanoscale dielectrophoretic spectroscopy of cells in solution
Abstract
The membranes of cells have been examined in solution with nanoscale resolution using dielectrophoretic force microscopy. Large non-uniform electric fields were created by applying oscillating voltage potentials to an electrically conductive atomic force microscope tip. The non-uniform electric fields resulted in a slight polarization of the surrounding material, and the resulting dielectrophoretic forces were measured by the atomic force microscope. The magnitude of the forces generated was dependent on the oscillation rate of the voltage potential and the dielectric properties of the material exposed to the electric field. A reason the dielectric properties of cell membranes are of interest is that malarial and cancerous cells have different dielectric properties than healthy cells. Separations of such cells based on dielectric properties have been done in previous studies. Past studies of cells using dielectrophoresis have used immobile electrodes and have been limited to analysis of cells that are free floating in solution. By utilizing an atomic force microscope tip as an electrode, immobilized cells such as a tissue sample can be analyzed with dielectrophoresis.
Degree
Ph.D.
Advisors
Simpson, Purdue University.
Subject Area
Analytical chemistry
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