| dc.description.abstract | Although advances in microfluidic technology have enabled increasingly
sophisticated biosensing and bioassay operations to be performed at the microscale,
many of these applications employ such small amounts of charged biomolecules (DNA,
proteins, peptides) that they must first be pre-concentrated to a detectable level.
Efficient strategies for precisely handling minute quantities of biomolecules in
microchannel geometries are critically needed, however it has proven challenging to
achieve simultaneous concentration, focusing, and metering capabilities with currentgeneration
sample injection technology. Using microfluidic chips incorporating arrays
of individually addressable microfabricated electrodes, we demonstrate that DNA can be
sequentially concentrated, focused into a narrow zone, metered, and injected into an
analysis channel.
The technique used in this research transports charged biomolecules between
active electrodes upon application of a small potential difference (1 V), and is capable of
achieving orders of magnitude concentration increases within a small device footprint.
The collected samples are highly focused, with sample zone size and shape defined solely by electrode geometry. In addition to achieving the objectives of the research
project, this setup was found to provide added functionality as a label-free biomolecule
detection technique due to the formation of light scattering phases of charged
biomolecules on top of the capture electrode. | en |
