Date of Award
Master of Science (MS)
Chemistry and Biochemistry
Xiao-Hong Nancy Xu
Multi-drug resistance (MDR) has been reported in both prokaryotes and eukaryotes; the pathogenic gram-negative bacteria Pseudomonas aeruginosa can extrude a variety of structurally and functionally diverse substrates via a number of membrane transport systems leading to MDR. We have developed a novel nanoparticle assay to characterize both the membrane transport system composed of the MexAB-OprM efflux pump and the membrane permeability induced by antibiotics. Gold (Au) and silver (Ag) nanoparticles were investigated for use as probes to explore membrane transport in P. aeruginosa.
The surface plasmon absorption (color) of Au nanoparticle solutions was found to change in the presence of Tris(2, 2'-bipyridine)ruthenium(II). The color change was both size and temperature dependent. The change in surface plasmon absorption was caused by the formation of Au nanoparticle aggregates.
The surface plasmon absorption (color) of Ag nanoparticles was found to correlate with nanoparticle size and was readily observable using dark field microscopy. Ag nanoparticles were used to measure real-time transformation of cell permeability and MDR efflux dynamics of individual bacteria cells at nanometer resolution. The MDR efflux dynamics data was validated using time-course fluorescence of bulk cell populations.
Brownlow, William J.. "Development of Single Nanoparticle Optical Assays for Imaging Single Living Cells" (2006). Master of Science (MS), thesis, Chemistry and Biochemistry, Old Dominion University, https://digitalcommons.odu.edu/chemistry_etds/27