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2nd Semester Project Idea
- We want to try and see if we can take the AuNP fibers that we formed last semester and be able manipulate them. In doing so we want to see if we can make them disappear and reappear by altering ions present in the original solution, as well as through the addition of cofactors, manipulation of pH, manipulation of temperature, and the addition of various solvents.
Variables that are of Interest
Removal of Gold Ions
- EDTA (Chelator) [SIGMA].
- If EDTA is able to break apart the fibers we would try and overwhelm the solution with additional gold ions to see if the fibers can be brought back.
- EGTA (Chelator)
- Salicylic Acid (Chelator)
- 2,2'-Bipyridyl (Chelator)
- Possible Removal of Gold Ions Via Precipitation see attached article [here]
- To test whether or not any of these chelators are able to break up the fibers we will add 10 times as many particles of chelator per gold particle. This is to ensure the chelator is in excess to make sure an effect is seen. If one chelator does in fact cause the fibers to disappear we will decrease this ratio to see is a smaller amount of chelator will cause the same effect.
Manipulation of Temperature
- We know that fibers are present in solution at a temperature of 80 degrees Celsius after synthesis.
- We don't know; however, if the fibers would still be stable if the temperatures were increased closer to boiling.
- One problematic thing about increasing the temperature in order to see if the fibers can withstand greater heat stress is the chance of loosing solvent. Perhaps refluxing the solutions after synthesis would allow us to answer this question without loosing solvent.
Manipulation of pH
- Test buffer solutions at pH 3, 5, 9, 11 to see effect on fibers.
- If effect is seen, we will neutralize the solution back to pH 7 by bombarding the solution with acid or base.
Manipulation of Ionic Strength/ Add Different Cofactors
Adding a new Water Miscible Solvent
- Water has a dipole moment of 1.85D
- Use Solvents with varying dipole moments that are still water miscible.
- 1,4 Dioxane- Dipole Moment .45D
- Acetone- Dipole moment 2.88D
- Dimethylformamide- Dipole moment 3.82D
- Chloroform?- Dipole Moment 1.04D
- DMSO- Dipole moment 3.96
Manipulation of Light and Optics?
Applying a Current?
Type of AuNP we plan to use to Test the Above Variables
- We know that Lysozyme linked AuNP's formed fibers at approximately the 45:1 Gold to Protein Ratio.
- As a result we are going to create lysozyme linked AuNP at ratios 50:1 and 110:1 to see if our varying treatments have the same effect on budding fibers and well established fibers.
- We will follow the same synthesis strategies as we did last semester; however, due to the large number of samples required for what we are proposing we will create many 1 ml aliquots for the 50 and 110 ratio of lysozyme linked AuNP's.
- Note that the number of gold particles present in the 1ml aliquots we plan on preparing is 1.505x10^17 particles.
More info on Lysozyme
If something Works How Do We Get Fibers Again?
- Source with peptide linked AuNP used transition metal ions in order to cause aggregation. Article Found [Here.]