Date on Master's Thesis/Doctoral Dissertation

6-2012

Document Type

Master's Thesis

Degree Name

M. Eng.

Department

Bioengineering

Committee Chair

Panchapakesan, Balaji

Author's Keywords

Biosensor; Circulating tumor cell; Carbon nanotube; Nanotechnology; Cancer biomarkers; Cancer detection

Subject

Breast--Cancer--Diagnosis; Nanotechnology; Biosensors

Abstract

Detection and profiling of circulating tumor cells (CTCs) is useful for cancer screening and for managing treatment of carcinoma patients. Label-free technologies aim to accomplish detection rapidly with small, simple micro and nano devices. Carbon nanotubes are favorable molecular sensors due to their unique properties. They have been widely investigated for immunosensing of cancer biomarkers as free proteins, but very little has been done to detect biomarkers in intact cells and much remains to be understood regarding the mechanism of their sensing. We have developed a simple carbon nanotube biosensor for epithelial cell adhesion molecule (EpCAM) for sensing EpCAM positive cells. Sensor fabrication steps involving minimal air exposure were employed which reduced random noise upon sample introduction to the device. Optimized sensors recognized specific interactions with EpCAM positive MCF-7 cells and did not recognize EpCAM negative MCF-10A cells, producing the same characteristic signal as for blank phosphate buffered saline samples (no interaction). A two sample t-test found that the specific and nonspecific signals were significantly different, p = 0.0235. Specific binding signals are attributed to the combined binding events and negative cell membrane potential.

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