Graduation Semester and Year

2009

Language

English

Document Type

Thesis

Degree Name

Master of Science in Biomedical Engineering

Department

Bioengineering

First Advisor

Samir M Iqbal

Abstract

Cancer is a disease that is the central focus of many a researcher's attention. As it is a disease that can spread very rapidly and can be fatal in many cases, its early detection and early treatment can dramatically change mortality. Towards the early detection of the disease, antibodies are most commonly used for the detection of cancer biomarkers. The use of antibodies in diagnostics has proven fruitful in the past. But advancements in molecular biology have introduced aptamers for diagnostic and therapeutic purposes. Aptamers are oligonucleotides or peptides that are usually synthesized by a selective process called SELEX. Aptamers are more advantageous as they are stable over wider physical conditions and have higher selectivity than antibodies. The Epidermal Growth Factor Receptor (EGFR) is a cell surface protein that plays a pivotal role during the tumorigenesis of the cancer cells. It is over-expressed during the onset and the course of cancer. .A biomarker sensor was designed to electrically detect proteins. For initial studies, the capture of R2Bm protein was demonstrated using double-stranded DNA that binds to it. Towards a practical application of the detection approach, EGFR capture and detection was also done. The EGFR was captured by the anti-EGFR RNA aptamer. To electrically detect the presence of the proteins, a Complementary Metal Oxide Semiconductor chip was fabricated with gold nano-electrodes for sensitive electrical detection of two model proteins. The electrical data obtained showed an increase in current by three orders when protein was captured between nano-electrodes in comparison with the control chips. The presence of the protein and the selective agent was confirmed in both cases. The use of CMOS chips in the detection system makes integration with more detection units more feasible. Designing a microarray for the simultaneous detection of many biomarkers is also possible with this detection. Also, to test the prototype device and technology of guided-more resonance,, the EGFR aptamer was immobilized on a titanium dioxide surface. The technology involves the analysis of shift in wavelength after a binding event. Upon analysis it was found that the protein was indeed bound to the aptamer on the titanium dioxide surface.

Disciplines

Biomedical Engineering and Bioengineering | Engineering

Comments

Degree granted by The University of Texas at Arlington

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