Document Type



Doctor of Philosophy



First Adviser

Vezenov, Dmitri V.

Other advisers/committee members

Moore, David T.; Glover, Kerney J.; Ou-Yang, Daniel


Many recent advances in DNA sequencing technology have taken advantage of single-molecule techniques using fluorescently-labeled oligonucleotides as the principle mode of detection. In spite of the successes of fluorescent-based sequencers, avoidance of labeled nucleotides could substantially reduce the costs of sequencing. This dissertation will describe the development of an alternative sequencing method, in which unlabeled DNA can be manipulated directly on a massively parallel scale using single molecule force spectroscopy. We demonstrated that a combination of a wide-field optical detection technique (evanescent field excitation) with dielectrophoretic (DEP) tweezers could determine the amount of the double-stranded character of DNA. This thesis discusses all aspects of the implementation of DEP tweezers, including the principle of operation, making of polymer force probes, numerical modeling of various designs, fabrication of electrode and disposable chip, force calibration, and the assembly of the device. The feasibility of this technique was demonstrated by conducting force spectroscopy on single DNA molecules using DEP tweezers. The development of such a single molecule force spectroscopy technique shows great potential for genome sequencing and other analytical applications that employ direct manipulation of biomolecules.

Included in

Chemistry Commons