As the title states, I have been making TEM images and reconstructions from a variety of NPN materials. I hope to correlate the underlying nanostructure with SERS activity eventually. These images show many different porosities, topographies and pore shapes. Wafer 1236 has been the bulk majority of my npMgF2 fabrication for my SERS experiments. …
Some of my recent cell culture work on Microporous MgF2 windows have shown vacancies in the cultured monolayer after fixation and staining. We should see a contiguous layer. To better understand my fixation, I seeded and cultured P10 RPE-19 cells at a high density on a coverglass and in a polystyrene dish for a week….
As we run our CCD (Central Composite Design for Optimizing SERS Substrates, SERS Measurements on 150C, 250C, 350C 1236 npMgF2), we have also been gathering TEM/SEM structural information about pore distributions and MgF2 grain structure. This post contains images about materials and compares them to information we know about wafer 1085, one of our original MgF2…
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I am attempting to manufacture a range of npMgF2 thicknesses as demonstrated in my recent CCD post. Yesterday, I undershot my thicknesses substantially, I believe because of construction vibrations in the building. However, this results in some of the thinnest npMgF2 structure I have ever been able to image. I was targeting 15 nm, but…
Now that we have a number of ways to quantify the nanostructure of different npMgF2/npAu film stacks, we can begin an optimization experiment for which combination of factors will be useful to us. To explore the space of outcomes, we have a set of Factors at a certain number of Levels. These produce a set…
I’ve been trying to recover a pore distribution from my 1085 MgF2 SERS wafer that had a ~60 nm pore size on average. This has been difficult with thinner, 50 nm NPN because there is less material to shape; it’s harder to stop at a certain point to get the right pore distribution. So, using…
One of the issues with my microporous MgF2 cell culture experiments is the apparent multilayer of cells that form on the freestanding area; ideally we would have a nice cell monolayer for imaging. It has been unclear if this was an effect of overseeding or if cells were migrating to the freestanding area. To this…
Summary Surface roughness is believed to impact the SERS effect. Rougher surfaces tend to produce more SERS activity. We can manipulate the npMgF2 surface by changing the deposition temperature, in the form of changing the grain nucleation, shifting the overall grain size and roughness. I performed TEM tomography and segmentation to pull out distributions of…
Summary My analysis of npMgF2 has relied heavily on both tomogram and segmentation processes. The tomogram generation has thus far been sufficient, giving enough detail to our eye to identify different structures, but turning the tomograms into 3d models has been a lot more labor intensive. Using a neural network classifier (Weka, out of a…