User:Megan L. Channell/Notebook/Horseradish/2013/08/28

From OpenWetWare

Jump to: navigation, search
Biomaterials Design Lab Main project page
Next entry

Synthesis of Gold Nanoparticles


The objective for this experiment comes from Dr. Hartings Lab Notebook. It is to synthesize two different sets of gold nanoparticles. In each synthesis, Au +3 is being reduced. In the first one it is by BSAm and in the second part of the experiment it is by citrate.


The protocol used for this section came from Dr. Hartings Lab Notebook. He

  • Note the stock concentration of HAuCl4 was 2.54 mM. BSA stock solution had a concentration of 15.6 muM. For the 90X concentration of gold in the solution compared to BSA, 1.81 mL of BSA was added. To be more precise, a pipet was used to measure out the specific amount of DI water to reach the 10 mL. This amount was 7.19 mL.



  • Note the stock concteration of HAuCl4 was .0249mM. The amount of 1.01% (w/v) of sodium citrate was 1.5 mL instead of 3 mL. Once it was cooled, a 1:50 dilution of 1 mL was prepared to run a UV-Vis spectrum. To prepare the UV-Vis sample, 20 μL of the solution and 980 μL of water were added and ran properly on the instrument.


This is the spectrum from the UV-Vis.  The sample was the 50X diluted Citrate-AuNP.

Image:Images/8/85/13 Megan L. Channell Citrate AuNP.jpeg


For Citrate-AuNP the UV-Vis was used to analysze the solution. With the results found, it could be analyzed using this reference. It had a maximum absorbancy of .031at 520 λ. The absorbance at the wavelength 450 was 0.02. The particle size in our solution was 12 nm. This was found by dividing the two absorbencies mentioned above and locating the number on the chart from the link. With knowing the particle size, the molar absorbtivity was found. It was 1.09E+8. USing the formula Concentration= Absorbance at 450/ Molar Absorbtivity at 450. The concentration of gold and citrate in the diluted solution was 1.83 x 10 -10M. The stock concentration was 9.17 x 10 -8M.

Personal tools