- Analyze AuNP/BSA solutions with UV-vis spectroscopy. Data will be posted next week.
- Make Tris buffer solutions at pH values of 8 and 10.
- Refer to Dhea Patel's entry for AuNP/BSA solution ratios, calculations, and images.
Tris Buffer Solutions
- 100 mL of 0.1 M Tris buffer solution requires:
MW Tris: 121.14 g/mol
(0.1 mol Tris/1 L) × (121.14 g Tris/1 mol Tris) = 12.114 g Tris/L
(12.114 g Tris/1 L) × 0.1 L = 1.2114 g Tris/0.1 L
Theoretical mass of Tris: 1.2114 g
- 1.2114 g of Tris buffer was added to 100 mL of H2O to make a 0.1 M Tris buffer solution.
- While stirring to ensure even distribution of particles, the pH of the solution was adjusted to 8.0 with drops of 1 M HCl. The total volume of HCl used was about 7 mL.
- Another 100 mL of 0.1 M Tris buffer solution was made and its pH was adjusted to 10.0 with drops of 1 M HCl. The total volume of HCl used was about 1 mL.
- Absorbance of AuNP/BSA solutions at concentrations ranging from 60 μM to 170 μM to determine the formation of AuNPs.
- A peak at around 530 nm for the 80 μM solution indicates the presence of AuNPs in solution. A visual confirmation was that the solution was also transparent purple in color.
- No peaks occurred for the other solutions, because no AuNPs formed. These solutions contained yellow-brown precipitate instead. The gold likely did not react with the BSA in the manner intended.
- The original AuNP solutions did not form nanoparticles, as the HAuCl4 reacted with the metal spatula. They were yellow in color and the higher ratio solutions contained brown precipitate.
- Visual analysis indicated that all but the 60 and 80 Au/BSA solutions of the second set of AuNP+BSA solutions contained fibers.
- Please refer to Keyun Wang's entry for more observations about the solutions.