Self Assembly of GeO₂ Nanoparticles: A Biomimetic Approach Public

http://ir.library.oregonstate.edu/concern/honors_college_theses/1n79h896c

Descriptions

Attribute NameValues
Creator
Abstract or Summary
  • Diatoms are single celled eukaryotic microalgae that self-assemble complex SiO₂ nanostructures by sillafin proteins within their cell wall. There has been increasing interest in mimicking the diatom’s silica self-assembly process for fabricating metal oxide nanoparticles, namely germanium dioxide (GeO₂). GeO₂ has a higher refractive index than silica, enabling it to be applied in a range of technologies such as fiber optics, optoelectronic devices, and complimentary metal oxide semiconductors. Current GeO₂ nano-fabrication methods require high pressure, temperature, and a great deal of time and resources. Our investigation offers a new approach, one based on the diatom’s natural process to manipulate GeO₂. We demonstrated that with this approach, GeO₂ nanoparticles could be fabricated under ambient conditions with a simple protocol. A metal oxide precursor, germanium (IV) ethoxide (GTE), and the protein poly-L-lysine as the biomimetic template (a simplified model of the diatom derived silaffin protein) were placed in artificial seawater (PBS). Three sets of GeO₂ nanoparticles were selfassembled from solutions that contained high (54 mg/mL), medium (28 mg/mL) and low (14 mg/mL) GTE concentrations. Scanning electron microscopy revealed that at high GTE concentrations, only oval shaped GeO₂ nanoparticles (160 nm diam.) were produced while at medium GTE concentrations, cubic (200 nm diam.) and oval (160 nm diam.) shaped nanoparticles were self-assembled. At low GTE concentrations, indefinite shapes were assembled, described as round agglomerates. Energy dispersive x-ray spectroscopy (EDAX) data at this low GTE concentration reveal elemental nitrogen within the sample, confirming the presence of –NH and/or –N-C bonds and therefore PLL. We hypothesized that the PLL protein acts as a template for the self-assembly of GeO₂ nanoparticles. This has been confirmed by EDAX assay revealing the presence of PLL in nanoparticle samples.
License
Resource Type
Date Available
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Non-Academic Affiliation
Rights Statement
Publisher
Peer Reviewed
Language
Replaces
Additional Information
  • description.provenance : Made available in DSpace on 2014-07-29T15:55:58Z (GMT). No. of bitstreams: 1Gessford_Makayla_UHCThesis.pdf: 1969012 bytes, checksum: bff22db2f1990e5fe8aa1ef2d5d70c27 (MD5)
  • description.provenance : Approved for entry into archive by Patricia Black(patricia.black@oregonstate.edu) on 2014-07-29T15:55:58Z (GMT) No. of bitstreams: 1Gessford_Makayla_UHCThesis.pdf: 1969012 bytes, checksum: bff22db2f1990e5fe8aa1ef2d5d70c27 (MD5)
  • description.provenance : Submitted by Kassena Hillman (kassena.hillman@oregonstate.edu) on 2014-07-28T22:35:33ZNo. of bitstreams: 1Gessford_Makayla_UHCThesis.pdf: 1969012 bytes, checksum: bff22db2f1990e5fe8aa1ef2d5d70c27 (MD5)

Relationships

Parents:

This work has no parents.

Last modified

Downloadable Content

Download PDF

Items