User:Michael S. Bible/Notebook/CHEM-671/690 Lab Notebook/2016/02/02
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Today's objective is to synthese AuNP+Rhodamine fibers. We will add Rhodamine at different concentrations (1, 0.1, and 0.01µM) and at different points in the synthesis (before and after fibers have been placed in the oven).
First, Nicole, Maxi, and Matt used volumetric flasks to make the following stock solution of lysozyme in DI water:
We used the same gold stock (3316µM) and rhodamine stocks (107.9, 10.79, and 1.079µM) as last week.
Our goal was to make 18 1mL fiber samples and 3 controls. For each sample, the concentration of lysozyme was 5.556µM and the concentration of gold was 0.25µM (these concentrations were ideal for fiber formation). Each sample and control had the following ingredients:
We added the Rhodamine to the samples either just before we put them in the oven (samples 1-9) or about an hour after we took the samples out of the oven (samples 10-18). For samples 10-18, we waited an hour to let the fibers cool before adding Rhodamine. We let all the samples sit overnight at room temperature.
The bolded parts indicate substitutions that were made for the controls.
Just as last week, we assumed the volume of rhodamine added (9.27µL) was negligible.
Fluorescence of Rhodamine B Calibration Curve
5 concentrations of Rhodamine B were prepared using volumetric flasks:
Samples were excited at 520 nm and the emission was scanned from 540-700 nm.
The following calibration curve was produced using the midpoint method to integrate the fluorescence curves:
Figure 1: The relationship between peak integration and concentration does not appear to be linear, so the graph has been fitted with a polynomial function. The use of this calibration curve should be limited to concentrations that fall within the range of 0.01 μM and 1.0 μM.