User:Puja Mody/Notebook/Chem 571: Gold Nanoparticles/2012/09/11

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Day 4

Goals

  • Run UV-Vis on AuNP/BSA samples 120, 128, 130, 132, 133, 134. and see if similar peaks are present
  • Run third UV-Vis on Tris buffer solutions of pH 8 and compare absorbances to the data collected last week.

Procedure

  • UV-Vis was run for the AuNP/BSA samples as well as water to account for our blank.
    1. UV/Vis was run on HAuCl4 and BSA solution with mole ratios of 120, 128, 130, 132, 133 and 134.
      1. The same cuvette was used and cleaned between each spectra.
  • The third UV-Vis was run on the Tris buffer solutions at pH 8. The first two rounds were run the previous time.
  • More AuNP/ BSA solution was made at a concentration of 170 and place in the oven for 4 hours at 80°C. These samples are to be used tomorrow and will be combined with the pH 10 tris buffer solution and have a UV-Vis run on them every hour.
  • Abigail E. Miller 13:50, 17 September 2012 (EDT):check your references to HAuCl4 and AuNPS.

Data/ Calculations

  1. Solution was made with a mole ratio of 170
    1. 2.4268M BSA solution was used
      1. m1v1=m2v2
      2. 24.266μM * (volume) = 1μM * 6mL
      3. .247mL BSA solution
    2. 2150μM HAuCl4 solution was used
      1. 2150μM * (volume) = 6mL *(1μM*170)
      2. .474mL HAuCl4 solution
  • 7 solutions in total were made to be used tomorrow.


Redone UV=Vis Image:Uv vis redone.png

Redone Uv-vis minus water abs. Image:Redone-abs_water.png

  • A UV-Vis was run for water and then those abs values were subtracted from the UV-Vis absorbance values collected by the samples. This allowed for us to account for a blank in the peak.


Links to spreadsheet and chart of redone UV-Vis: [Excel]

Tris Buffer AuNP all three UV-Vis data


Link to spreadsheet and charts of the 3 UV-Vis data on the solutions of AuNP with tris buffer.

There was no noticeable change between the three absorbance spectras. The data was further broken down to show the no change. The data spreadsheets also include graphs comparing each concentration for each abs. spectra (ex. 1x10-1 for rounds 1-3).

Conclusions

  • For the redone AuNP/BSA UV-Vis tests done. Instead of just one peak at 550nm, there was an uncharacteristic peak at around 490-500nm as well. As a result, distilled water was also tested to see if it had been a factor in causing an adjustment to the same. In the data spreadsheet, the UV-Vis data for each of the samples then had the UV-Vis data for water subtracted from it in order to test if it was the water that had caused the peak. The graphs clearly show that without the water, the background, the second peak was removed.
  • Based on graphs: The gold nano particle/ BSa fibers were placed in the Buffer solution. But based on the graph data which does that there was no increase in the concentration of the gold nano particles in the tris buffer. Thus it can be concluded that the nano particle fibers did not dissolve in the buffer.






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