Gold Nanoparticle Synthesis
The goal of this experiment is to synthesize citrate protected gold nano particles of 40-45nm diameter.
Dopamine solution will also be made to synthesize Polydopamine coated AuNPs.
- Prepare stock solutions
- Dissolve HAuCl4 in water to have a solution of 10mM
- Dissolve 250mg of the citrate sodium salt into 25mL of water
- In a beaker mix 50mL of water and a volume of the gold stock solution corresponding to 1.214*10^-2 moles of Gold
- Bring solution to a boil
- Add a 0.5mL of the citrate sodium solution and reflux for 30 minutes
- Note color change from dark blue to red
Polydopamine Coated AuNPs
- Dissolve dopamine in 100mL Tris Buffer to have a 10mM solution at pH=8.5
- Mix 17mL of AuNP solution with 17mL of the dopamine solution
- Stir under air at room temperature for 1 hour
- Purify by centrifuging and then redisperse in water.
- Filtrate through syringe filters with cellulose acetate membranes with pore size of 1um
- Make 2 solutions.
- to be stored over night on lab bench
- to be stored over night in the refrigerator
- A buffer was made using 0.3milimoles of acetic acid and 6 milimoles of potassium acetate
- The final pH was about 5
- A 10^-6M HRP solution was made using the buffer
- Make Protein-AuNP solutions
- A 10^-7M solution was made by adding 1mL of the HRP solution to 9mL of AuNP solution
- A 10^-8M solution was made by adding 0.1mL of the HRP solution to 9.9mL of AuNP solution