User:Sanuja Mohanaraj/Notebook/Experimental Biochemistry 1 Fall 2017/2017/08/30

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Amino Acid Stock Solutions Preparation First, three amino acids are selected before preparing each stock solution: L-Isoleucine (aliphatic), Arginine (amine) and Phenylalanine (aromatic). Next, 1.6398mg of L-isoleucine is measured out into a weighing boat and transferred into a 50mL volumetric flask. Deionized water is then added to the volumetric flask to the mark, achieving a final concentration of 250μM. The volumetric flask in then sealed using parafilm, and stored. This process is repeated using separate 50mL volumetric flasks, each time using 2.1775mg of Arginine and 2.0649mg of Phenylalanine. Finally, once all three solutions are prepared, the absorbance and fluorescence of each amino acid stock solution are measured. Au Nanoparticles Solutions Preparation Three different molar ratios of the gold nanoparticles and each amino acid solution (Au:AA) are prepared, and the pH of each solution is then measured as follows: Phenylalanine (aromatic) Ratio 1:20 -- pH 3.327 Ratio 1:80 -- pH 3.273 Ratio 1:160 -- pH 3.244 L-isoleucine (aliphatic) Ratio 1:20 -- pH 3.235 Ratio 1:80 -- pH 3.292 Ratio 1:160 -- pH 3.338 Arginine (amine) Ratio 1:20 -- pH 3.372 Ratio 1:80 -- pH 3.260 Ratio 1:160 -- pH 3.272 Calculations moles / volume = molarity moles / 50mL = 250μM of each amino acid stock solution moles = 1.25e-5 moles of each amino acid stock solution L-isoleucine grams / (131.18 g/mol) = 1.25e-5 moles grams = 1.6398mg of L-isoleucine Phenylalanine grams / (165.19 g/mol) = 1.25e-05 moles grams = 2.0649mg of phenylalanine Arginine grams / (174.2 g/mol) = 1.25e-5 moles grams = 2.1775mg of arginine Results The solutions that were made did not form gold nanoparticles, so the solutions were remade with a lower Au:AA molar ratios over a different pH range, the following week.