This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).
With this award from the Major Research Instrumentation (MRI) program, the Departments of Chemistry, Earth Sciences, Biology, Physics and Anthropology at the University of Northern Colorado will acquire a Scanning Electron Microscope (SEM) equipped with energy dispersive spectroscopy (EDS) to support research activities in these Departments. This instrumentation will enable significant advances in projects focused on materials science, geology, biology, anthropology and the environment. Examples of projects include: 1) the investigation of how the mineral zircon can provide critical information regarding the formation of mountain belts, 2) the determination of elemental composition in intermetallic materials, 3) the investigation of monolayer formation and stability on surfaces, with respect to studying specific receptor-analyte interactions, 4) the elucidation of the uptake and distribution of selenium in several filamentous fungi, 5) the study of the tool cut and wear marks on ancient stone and bone tools to help in determining their use and function, and 6) the study of plant cell structure as a function of temperature stress. In addition, the SEM will feature in a number of outreach and education activities of the University, including the education of pre-service K-12 teachers, and ongoing collaborations with Laramie County Community College and the Greeley/Weld County Forensic Laboratory.
Scanning electron microscopy is a widely used technique for providing an image of a sample surface. The image is obtained from scanning the surface with a beam of electrons. Energy dispersive spectroscopy is combined with a SEM to provide elemental analysis i.e. chemical characterization of the sample. The SEM/EDS acquisition will be fully integrated into faculty members' research programs, and will be used by research students from a wide variety of science disciplines. The wide-ranging education and outreach activities carried out by the University of Northern Colorado will expose a large number of members of the public to the utility of SEM imaging in helping to answer important questions in science.
1) When some fungi were grown in the presence of large quantities of Se a strong red hue developed in the fungal colony or growth media suggestive of the presence of crystalline elemental selenium. Two allotropic forms of elemental selenium, alpha and beta cyclo-octaselenium are known to be red in color, and it was hypothesized that some of the fungi were reducing Se to its elemental form known to be less biologically available and therefore, less toxic. Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray Spectroscopy (EDS) were used to provide photographic evidence and additional qualitative elemental analysis of crystalline structures found on hyphae, respectively. All fungi were found to produce crystals when grown in the presence of at least one of the oxoanionic forms of selenium provided (SeO42- and SeO32-). The EDS analysis of the crystal structures showed large variation in elemental composition between the different genera of fungi with Fusarium acuminatum showing both consistent crystal production and crystals with the highest Se content. 2) Two students conducting research with Co P.I. Baird used the SEM to characterize zircon, a zirconium silicate mineral. An honors undergraduate student separated zircon from the Hyde School Gneiss in the northwest Adirondacks and used the SEM to characterize the zircon’s internal zoning by secondary and backscatter electrons, and by color cathodoluminescence. This was done in an attempt to reveal the origin of the rock as zircon zoning characteristics are partially controlled by the processes that form the rock. Results were written up in an undergraduate honors thesis entitled "Petrographic and cathodoluminscence characterization of zircons in the Hyde School Gneiss, Adirondack Lowlands, New York: Implications for determining the protoloth." M.A. student, Sean Figg, separated zircons from metamorphosed igneous rocks collected in northern Sweden. The SEM was used to characterize the zircon’s internal zoning by secondary and backscatter electrons, and by color cathodoluminescence, to ensure the zircon grew by one single event. This information was used to ensure the correct method by which to isotopically date the zircon was chosen. Results were written up in Mr. Figg’s M.A. thesis entitled "U-Pb zircon dating and geochemical analysis of the Kebne Dyke Complex in the Rabots, Kuopervagge, and Tarfala Valleys, Kebnekaise Massif, northern Sweden." 3) Co-principal investigator Robert Brunswig has worked with anthropology undergraduate students to develop and implement his Archaeological Materials Sourcing Project. The project is based on the capacity of specific SEM instrument modules to characterize and identify geologic sources for prehistoric flaked and ground stone tools such as projectile points, knives, scrapers, and grinding stones and identifying clay sources for prehistoric pottery. One of the SEM detectors, its EDX (energy dispersive X-Ray spectroscopy) module, is being utilized to determine light wave-length emission patterns (SEM-CL) and elemental component spectrographic composition of raw material (lithic and clay) samples and match their sources with artifacts recovered from archaeological sites in the Colorado Rocky Mountains. Over the past two years, SEM material chemical characterization analyses have been made for stone tool artifacts and lithic source material held in the university’s comparative collection of well-documented lithic source materials from Colorado, Texas, New Mexico, Oklahoma, Arizona, South Dakota, North Dakota, Wyoming, and Montana. Previous to the SEM sourcing project, physical, petrographic, and Ultra-Violet (UV) short and long wave analysis data had been recorded with the majority of the collection’s samples. The sourcing project using the SEM system allows the addition of chemical component signatures to be added to the lithic collection’s catalogue and further increase our ability to identify geologic sources of artifacts recovered in our archaeology field projects. Over a period of 18 months, a total of 112 lithic samples have been subjected to SEM EDX analysis. In most cases, multiple areas of the sample surfaces were recorded in order to gain a cross-section of chemical signatures and "smooth-over" and detect chemical variation across the sample surface, a common source of inaccuracy in EDX-based analysis and much less of a problem in the use of higher resolution XRF "laser-ablation" instruments more commonly used in lithic materials studies. 4) The structure of the protein fibrinogen is well understood and has been characterized in detail using atomic force microscopy (AFM). Our studies build on previous work by investigating the effects of a snake venom toxin (a thrombin-like serine proteinase) or human thrombin on fibrinogen clotting using AFM and scanning electron microscopy (SEM). Studies were performed to image fibrinogen in buffered solution, normal fibrinogen conversion to fibrin in the presence of thrombin, and fibrinogen coagulation in the presence of a snake venom toxin. Images were collected at time intervals to determine the progression of the effects of the snake venom toxin on fibrin formation. These images were then compared to normal fibrin formation
