User:Omar Choudary/Notebook/Omar Choudary CHEM-571 AU-2011/2012/2012/02/08

Chem-571

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Objective Prepare another BSA control solution Synthesize 70 and 166 molar ratio AuNP solutions Prepare Tris re-folding buffer Description BSA Control: 1 mL 17.7 μM BSA + 1 mL 2.85 mM HCl + 8 mL H2O, and then placed in oven (80°C) for 2 hours AuNP Mixtures: Au/BSA (70) Ratio: .42 mL HAuCl4 + 1 mL BSA + 8.5 mL H2O Au/BSA (166) Ratio: 1 mL HAuCl4 + 1 mL BSA + 8 mL H2O Tris Re-Folding Buffer: 1.514 g Tris + 3.51 mL 0.948M HCl and then filled to 250 mL with H2O. pH = 8.73 Data The 70 Au/BSA molar ratio, yielded a light pink solution. This was similar to the expected result. There are some indicators of contamination in the test tube which could have been the cause for this result. The 166 Au/BSA molar ratio yielded pink fibers in clear solution, which was the expected result. The pH of the Tris Buffer was determined to be 8.73. Notes The tris refolding buffer will be used next week to raise the pH of the solutions after the AuNP synthesis to the 8 to 9 pH range. The higher pH is a mandatory step for tagging the lysine residues in the BSA with the dye which need to be deprotonated (pKa = 8.95 at the amino group). The BSA control was made with the same amount of acid but with HCl instead of HAuCl4; so the solution is identical to the AuNPs except the Gold is absent.