# User:Dominique Brager/Notebook/481 Notebook/2017/09/05 Biomaterials Design Lab Main project page Previous entry      Next entry ## Objective

• Remake solutions with low Au:amino acid ratios over different pH range
• Use the following volumetric ratios of Au:AA:NaOH
• (1) 1:1:0.5 (2) 1:1:1
• Switch to the 1 M NaOH solution and prepare mixtures using the following volumetric ratios
• (3) 1:1:0.1 (4) 1:1:1
• Calculate theoretical pH assuming [AA] has negligible effect
• Titration Stock Solution Prep
• Tritration Standardization

## Description

• Theoretical pH Calculations

Mol of HAuCl4 (2.5 mM)

1 mL* 1 L/1000 mL * 2.5 mmol/1 L * 1 mol/1000 mmol = 2.5*10^-6 mol HAuCl4

Mol of NaOH (5 mM and 1 M stock)

0.5 mL * 1 L/1000 mL * 5 mmol/1 L * 1 mol/1000 mmol = 2.5*10^-6 mol NaOH
1 mL * 1 L/1000 mL * 5 mmol/1 L * 1 mol/1000 mmol = 5*10^-6 mol NaOH
0.1 mL * 1 L/1000 mL * 1 moll/1 L * 1 mol/1000 mmol = 1*10^-4 mol NaOH
1 mL * 1 L/1000 mL * 1 mol/1 L * 1 mol/1000 mmol = 1*10^-3 mol NaOH

Mol of NaOH - Mol of HAuCl4 = Mol of OH

1. 0
2. 2.5*10^-6 mol
3. 9.75*10^-5 mol
4. 9.975*10^-4 mol

Concentration = Mol NaOH/ 10mL * 1000mL/ 1 L

pH = -log(concentration)

Ratio 1:1:0.5 --> pH 7
Ratio 1:1:1 --> pH 10.4
Ratio 1:1:0.1 stock --> pH 11.9
Ratio 1:1:1 stock --> pH 13
• Titration Stock Solution Prep

(0.0200 L AA)*(0.000250 mol/L AA)*(1 mol NaOH/mol AA)/(0.0200 L NaOH) = 0.000250 M NaOH

M1V1 = M2V2

500mL * 2.5*10^-4 M NaOH = x * 1M NaOH ------> x = 0.125mL

## Data

Amino Acid Solutions prepared last week did not work at any concentration.

Gold Nanoparticle and Nano fiber solutions prepared with BSA

From left to right Au:BSA ratio: 60, 90, 120, 150

Nano particles made in 60, 90, and 120. Nano fibers made in 120 and 150. 90 darker than 60.