Publication Date
2017
Document Type
Thesis
Committee Members
Ioana Sizemore, Ph.D. (Advisor); David Dolson, Ph.D. (Committee Member); Steven Higgins, Ph.D. (Committee Member)
Degree Name
Master of Science (MS)
Abstract
The extensive use of silver nanoparticles (AgNPs) in consumer products and research is accompanied by their inevitable release into the environment. While the environmental fate of AgNPs is still under investigation, most in vitro and in vivo studies agree that the main toxicity of AgNPs is directly related to the release of Ag+ ions from AgNPs. In this study, cloud point extraction (CPE) was combined with tangential flow filtration (TFF) for the enhanced separation of AgNPs and Ag+ from aqueous colloids and biological matrices. The feasibility of the CPE-TFF method was demonstrated on four colloidal (borohydride-, PVP-, citrate-capped and uncapped AgNPs) and three cellular matrices (Escherichia coli, Vero 76 cells, and mitochondria extracts). The addition of a 1-kD TFF step to CPE was found to boost the total Ag recovery to over 93.4±8.4% for the aqueous colloids and 90.2±8.5% for the mammalian and bacterial cells. The preservation of the size, shape, and optical properties of AgNPs during the CPE-TFF manipulation was confirmed by transmission electron microscopy and UV-Vis absorption spectroscopy. CPE-TFF facilitated the investigation of fundamental nanotoxicity questions such as the redox interconversion of the two Ag species within mitochondria or colloids as a function of time and concentration. CPE-TFF is a simple, time- and cost-effective separation method of AgNPs and Ag+ that could find numerous other applications in the environmental health and safety of nanotechnology area.
Page Count
55
Department or Program
Department of Chemistry
Year Degree Awarded
2017
Copyright
Copyright 2017, all rights reserved. My ETD will be available under the "Fair Use" terms of copyright law.
ORCID ID
0000-0003-1270-1501
