Date of Graduation

8-2012

Document Type

Thesis

Degree Name

Master of Science in Chemical Engineering (MSChE)

Degree Level

Graduate

Department

Chemical Engineering

Advisor

Shannon Servoss

Committee Member

Keith Roper

Second Committee Member

Ryan Tian

Third Committee Member

Xianghong Qian

Keywords

Applied sciences; Pure sciences; Disease detection; Elisa; Peptoid; Self-assembly; Sensor

Abstract

Poly-N-substituted glycines (peptoids) are a very versatile family of synthetic molecules that can be customized for any number of applications. In this study, we chose to use peptoids as a foundation for sandwich ELISA microarray analysis with a long term goal of creating an early detection device for complex diseases such as cancer. The peptoids were designed to self-assemble into microspheres to be used in coatings on the surface of the microarray substrates to increase the surface area available for antibody attachment. This increased antibody density would lead to an increase in the microarray analysis sensitivity and dynamic range. Studies were completed to determine the sequence characteristics and application process conditions necessary to form robust, uniform surface microsphere coatings. Polarity characteristics throughout the peptoid sequences were studied to determine how the choice and placement of charged functional groups effects self-assembly. The affect of secondary structure on the formation of microspheres was also studied, as we believe aromatic stacking mechanisms between the molecule's helical faces help with microsphere stabilization. Through this research, it was found that peptoids with a combination of chiral and aromatic side-chains accounting for at least two-thirds of the residues contain the helical and hydrophobic characteristics necessary to form self-assembled microspheres. An additional study was completed to investigate the effects of application process conditions on the uniformity of the coatings. We have shown that peptoid based microspheres have the ability to form uniform surface coatings under normal processing conditions, and are an exciting new avenue for early disease detection.