DOI
https://doi.org/10.25772/C27W-8A28
Defense Date
2013
Document Type
Thesis
Degree Name
Master of Science
Department
Chemistry
First Advisor
Julio Alvarez
Abstract
Zeta potential is one of the tools to measure the surface charge of materials, and Alvarez et al. have developed a microchannel device to measure zeta potentials in real time for label-free sensing using immobilized receptors on microchannel surfaces. However, the challenge has been the charge interference of surface modifiers on analyte detection. Therefore, it was necessary to find the best strategy to regenerate minimal surface charge after modifying the channel with polymer films that would anchor the affinity groups for the analyte. It was demonstrated that adsorption of positively and negatively charged analytes were monitored via real time zeta potential measurements by using surface-immobilized polystyrene nanospheres, and the best discrimination of analyte binding on the nanoparticles was observed when the underlying film was a non-ionic polymer. Titanium oxide nanoparticles (TiO2) were immobilized on microchannels modified with non-ionic polymers to investigate if the surface charge of the microchannel was induced by the concomitant surface charge reactions of the TiO2 nanoparticles upon UV exposure. Analysis by XPS indicates that desorption of proteins monitored by zeta potential changes are induced by UV exposure.
Rights
© The Author
Is Part Of
VCU University Archives
Is Part Of
VCU Theses and Dissertations
Date of Submission
January 2014