Objective
Today's objective is to practice synthesizing AuNP+Rhodamine fibers. We will also practice adding Rhodamine at different concentrations and at different points in the synthesis. We decided not to add the Rhodamine in the middle of the synthesizing process.
Protocol
First, we used stock solutions of gold and Rhodamine from last week and we used a volumetric flask to make the stock solution of lysozyme in DI water:
Calculations:
(0.01482 g Lysozyme)(1 mol/14307 g)(10^6 µ mol/1 mol)(1/25 mL)(1000 mL/1 L)= 41.43 µM
- 25mL of 41.33µM lysozyme stock solution
- Molecular weight of lysozyme solid is 14307g/mol
Our goal was to make 20 1mL fiber samples and 1 1ml Rhodamine control. For each sample:
- The concentration of gold would be 250µM (i.e. we'd add 75.39µL of our gold stock)
- The concentration of lysozyme would be 5.556µM (i.e. we'd add 134.11µL of our lysozyme stock)
- We would bring the total volume up to 1mL using DI water (i.e. we'd add 790.5µL to each sample)
These gold and lysozyme concentrations should be ideal for forming fibers.
We were also going to add Rhodamine to the fibers at different points in the synthesis in order to determine which time allowed the maximum percentage of Rhodamine to be incorporated into the fibers. Additionally, were were going to add varying concentrations of Rhodamine to determine the best concentration to use for maximum incorporation of the dye into the fibers.
- We did three serial dilutions of the 1079µM stock of Rhodamine (diluted by a factor of 10 for each dilution). This way, we could change the concentration of Rhodamine added to each sample but keep the volume of Rhodamine added constant.
- The volume of Rhodamine added to each sample would be 9.27µL
- NOTE: we assumed the volume of Rhodamine added to each sample would be negligible, so when doing concentration calculations, we assumed the total volume of each sample would be 1000µL (even though technically it would be 1000µL-9.27µL).
We made the following samples to test these two variables:
| Sample #
|
Time in Synthesis that Rhodamine is Added
|
Concentration of Rhodamine
|
| 1
|
Before heating samples in oven
|
0µM (control)
|
| 2
|
Before heating samples in oven
|
0.01µM
|
| 3
|
Before heating samples in oven
|
0.01µM
|
| 4
|
Before heating samples in oven
|
0.01µM
|
| 5
|
Before heating samples in oven
|
0.1µM
|
| 6
|
Before heating samples in oven
|
0.1µM
|
| 7
|
Before heating samples in oven
|
0.1µM
|
| 8
|
Before heating samples in oven
|
1µM
|
| 9
|
Before heating samples in oven
|
1µM
|
| 10
|
Before heating samples in oven
|
1µM
|
| 11
|
After samples have cooled
|
0µM (control)
|
| 12
|
After samples have cooled
|
0.01µM
|
| 13
|
After samples have cooled
|
0.01µM
|
| 14
|
After samples have cooled
|
0.01µM
|
| 15
|
After samples have cooled
|
0.1µM
|
| 16
|
After samples have cooled
|
0.1µM
|
| 17
|
After samples have cooled
|
0.1µM
|
| 18
|
After samples have cooled
|
1µM
|
| 19
|
After samples have cooled
|
1µM
|
| 20
|
After samples have cooled
|
1µM
|
| 21
|
Rhodamine control with HCl
|
1µM
|
For the control samples, we were going to add 9.27µL of DI water instead of Rhodamine.
Fluorescence Parameters:
Start 540 nm
End 700 nm
Ex: 520 nm
| 
Project name
