Purpose/Objective
- Test Solvents and Ionic Strength on all ratios of AuNP's.
- Aliquot out AuNP's Made yesterday.
- Take notes on the effect of Chelator's and pH.
- Test the effect of SDS.
- Test the effect of Pepsin.
Pre-Procedure Data
- Take note that both the 40:1 and 50:1 AuNP's created fibers.
- As a result we now have 5 different tubes of AuNP's. We have 40:1 with and without fibers. 50:1 with and without fibers. Finally we have 110:1 with fibers. We aren't concerned that the 40:1 and 50:1 ratio formed fibers because the line to forming fibers in this ratio area is extremely temperamental. Due to this fact we are going to use all AuNP samples for all subsequent variable analysis.
Procedure
Solvent Tests
- .5 ml of DMF, DMSO, chloroform, 1,4 Dioxane, and acetone were added to a 1ml aliquot of each ratio AuNP we've synthesized.
- Tubes were vortexed and were allowed to sit until next class.
- Please note that no immediate change was noticed.
Ionic Strength
- Bulk amounts of Sodium chloride, Potassium Chloride, Magnesium Chloride, and Calcium Chloride were added to each ratio of AuNP's. No specific amount of salt was added because we had the chemical in bulk and if any effect is seen we plan to investigate more with a fine tooth comb.
- No immediate change was noted. We will reevaluate the aliquots next class.
Random Tests
- Because no variables seem to be effecting the breakdown of the fibers it was recommended to see if SDS, sodium dodecyl sulfate, had an effect on the fibers. In addition pepsin was added to see if by digesting the proteins the AuNP's would go back into solution.
- .1 g of SDS was added to each ratio of AuNP's to see if their was an observable effect.
- A bulk amount of pepsin was added to a single tube of 50:1 AuNP's. We only made one tube of this because in theory the pepsin should chew up the protein on the AuNP's and make the protein loose its function. We just thought if anything should be able to break apart these fibers if the stability is due to the protein it would be pepsin.
Data
- Looking at the chelator tubes and the pH effected tubes it didn't appear that any treatments were able to break apart the fibers.
- One interesting result was 2,2 bipyridine was apart to make fibers fall out of solution in a 40:1 ratio tube unlike any other treatment.
In addition, it appears that more acidic solutions also made AuNP's fall out of solution in the 40:1 ratio tubes. Basic pH seemed to allow the AuNP's to say suspended but could reverse the process of fiber formation.
- It didn't appears that their was a clear difference between associating and non-associating bases when looking at pH.
- These are just sketch of what we saw. Next class we will be taking pictures of each treatment for a more detailed level of analysis.
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Biomaterials Design Lab
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