Novel electrophoresis devices for protein and DNA separation and identification
have been presented and studied. The new device utilizes a contact resistance change
detection method to identify protein and DNA in situ. The devices were prepared with a
microelectronic micromechanical system (MEMS) fabrication method. Three model
proteins and six DNA fragments were separated by polyacrylamide gel microchannel
electrophoresis and surface electrophoresis. The detection of the proteins or DNA
fragments was accomplished using the contact resistance increase of the detection
electrode due to adsorption of the separated biomolecules. Key factors for the success of
these devices were the optimization of fabrication process and the enhancement of
detection efficiency of the devices. Parameters, such as microchannel configuration, size
of electrode, and affinity of protein or polyacrylamide gel to the microchannel sidewall
and bottom surface were explored in detail. For DNA analysis, the affinity to the bottom
surface of the channel was critical. The surface modification method was used to
enhance the efficiency of the microchannel surface electrophoresis device. The
adsorption of channel separated protein and DNA on the detection electrode was
confirmed with the electron spectroscopy for chemical analysis (ESCA) method. The
electrical current (I) from the protein microchannel electrophoresis was usually noisy
and fluctuated at the early stage of the electrophoresis process. In order to remove the
current perturbation, an amorphous silicon (a-Si:H) thin film transistor (TFT) was
connected to the microchannel device. The self-aligned a-Si:H TFT was fabricated with
a two-photomask process. The result shows that the attachment of the TFT successfully
suppressed the current fluctuation of the microchannel electrophoresis process. In
summary, protein and DNA samples were effectively separated and detected with the
novel TFT-driven or surface microchannel electrophoresis device.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/1439 |
| Date | 17 February 2005 |
| Creators | Lee, Hyun Ho |
| Contributors | Kuo, Yue |
| Publisher | Texas A&M University |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Dissertation, text |
| Format | 2643561 bytes, electronic, application/pdf, born digital |
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