Rapid sensing platforms for biomolecular, cellular and bio-nanomechanical detection
Abstract
Most currently available biomolecular and cellular detection methods require either time-consuming steps for target-labeling and signal-amplification or expensive equipment. Similarly, fluorescence-based methods and sophisticated and costly tweezing methods have been used to study bacteriophage phi29 DNA packaging motor, which is one of the nature's strongest nanomotors with potential for gene and drug delivery. The first goal of this study is to develop rapid and fluorescent label-free sensing methods for detecting biomolecules and whole cells. The second goal is to again develop a robust, simple and fluorescent label-free system for direct visual investigation of the dynamics of the phi29 DNA-packaging motor. The second and third chapters of the dissertation comprise the development of two optical detection methods: the optical transmission cell detector and immunomagnetic diffractometry for biomolecular detection. The cell detector has the ability to detect as few as 45 Escherichia coli cells and 34 Bacillus anthracis spores. The immunomagnetic diffractometry has the sensitivities of 700 fM (20 pg/mL) for detecting folate receptor (a serum marker indicative of various cancers) and 64 pM (24.5 pg/mL) for detecting S-adenosyl homocysteine (a potential diagnostic marker for cardiovascular disease). The forth chapter is based on the development of a magneto-mechanical system for direct visual observation of the phi29 motor activity at single molecular level in bright-field. By using this system we analyze the phi29 DNA packaging dynamics and visually demonstrate that the phi29 virus can transport a cargo that is 4 orders of magnitude larger than itself.
Degree
Ph.D.
Advisors
Peroulis, Purdue University.
Subject Area
Biomedical engineering|Electrical engineering
Off-Campus Purdue Users:
To access this dissertation, please log in to our
proxy server.