User:Carly M. Montanero/Notebook/CHEM-571/2013/08/28: Difference between revisions

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{|{{table}} width="800"
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|style="background-color: #EEE"|[[Image:owwnotebook_icon.png|128px]]<span style="font-size:22px;"> Project name</span>
|style="background-color: #EEE"|[[Image:BDLlogo_notext_lr.png|128px]]<span style="font-size:22px;"> Biomaterials Design Lab: Fall 2013</span>
|style="background-color: #F2F2F2" align="center"|<html><img src="/images/9/94/Report.png" border="0" /></html> [[{{#sub:{{FULLPAGENAME}}|0|-11}}|Main project page]]<br />{{#if:{{#lnpreventry:{{FULLPAGENAME}}}}|<html><img src="/images/c/c3/Resultset_previous.png" border="0" /></html>[[{{#lnpreventry:{{FULLPAGENAME}}}}{{!}}Previous entry]]<html>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</html>}}{{#if:{{#lnnextentry:{{FULLPAGENAME}}}}|[[{{#lnnextentry:{{FULLPAGENAME}}}}{{!}}Next entry]]<html><img src="/images/5/5c/Resultset_next.png" border="0" /></html>}}
|style="background-color: #F2F2F2" align="center"|<html><img src="/images/9/94/Report.png" border="0" /></html> [[{{#sub:{{FULLPAGENAME}}|0|-11}}|Main project page]]<br />{{#if:{{#lnpreventry:{{FULLPAGENAME}}}}|<html><img src="/images/c/c3/Resultset_previous.png" border="0" /></html>[[{{#lnpreventry:{{FULLPAGENAME}}}}{{!}}Previous entry]]<html>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</html>}}{{#if:{{#lnnextentry:{{FULLPAGENAME}}}}|[[{{#lnnextentry:{{FULLPAGENAME}}}}{{!}}Next entry]]<html><img src="/images/5/5c/Resultset_next.png" border="0" /></html>}}
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# Add 7.19 ml deionized water to the volumetric flask.
# Add 7.19 ml deionized water to the volumetric flask.
# Transfer the solution to a test tube and cap with aluminum foil.
# Transfer the solution to a test tube and cap with aluminum foil.
# Heat in the oven at 80C for three hours.
# Heat in the oven at 80°C for three hours.
# Transfer the solution to a plastic falcon tube.
# Transfer the solution to a plastic falcon tube.


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# Cool to room temperature and measure the final volume.
# Cool to room temperature and measure the final volume.
# Determine the final concentration of gold and citrate.
# Determine the final concentration of gold and citrate.


==Figures==
==Figures==
* Spectrum from UV-VIS of 50x Diluted Citrate-AuNP Solution
* Spectrum from UV-VIS of 50x Diluted Citrate-AuNP Solution
[[Image:UV-VIS Spectrum of UV-Vis of 50x Diluted Citrate-AuNP.png]]
[[Image:UV-VIS Spectrum of UV-Vis of 50x Diluted Citrate-AuNP.png|650px|]]
 
[[User:Matt Hartings|Matt Hartings]] In the future, your spectra are going to be much easier to read if they only have lines (and no symbols).


==Calculations from Part 2==
==Calculations from Part 2==
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==Observations==
==Observations==
* The final volume of Citrate-AuNP solution was 31.0 ml.
[[User:Matt Hartings|Matt Hartings]] based on this final volume (and initial concentration) what is your concentration of gold?
* The progression of color change in Part 2 was light purple → dark purple → magenta → burgundy → deep red.
* The progression of color change in Part 2 was light purple → dark purple → magenta → burgundy → deep red.
* The final color of the BSA-AuNP solution was dark purple.

Revision as of 09:14, 9 October 2013

Biomaterials Design Lab: Fall 2013 <html><img src="/images/9/94/Report.png" border="0" /></html> Main project page
Next entry<html><img src="/images/5/5c/Resultset_next.png" border="0" /></html>

Objective

Synthesize two different sets of gold nanoparticles. In one set, Au3+ is reduced by a protein (bovine serum albumin, BSA) and the synthesized nanoparticle is also surrounded and stabilized by BSA. In the second set, Au3+ is reduced by citrate, and the AuNP is stabilized by citrate in solution. The BSA-AuNPs are purple in color and the citrate-AuNPs are more of a burgundy (reddish) color.

From Dr. Hartings


Procedure

Part 1: BSA-AuNP Synthesis

  1. Add 1.00 ml of 2.54 mM gold solution (HAuCL4) to a 10 ml volumetric flask.
  2. Add 1.81 BSA (90x more gold than BSA) to the volumetric flask.
  3. Add 7.19 ml deionized water to the volumetric flask.
  4. Transfer the solution to a test tube and cap with aluminum foil.
  5. Heat in the oven at 80°C for three hours.
  6. Transfer the solution to a plastic falcon tube.

Part 2: Citrate-AuNP Synthesis

  1. Take 50 ml of 0.254 mM gold solution (HAuCL4) from the stock solution.
  2. Heat the solution to boiling while stirring and covered with a watch glass.
  3. Add 1.5 ml of 1.01% (w/v) sodium citrate.
  4. Boil the solution for another 40 minutes.
  5. Cool to room temperature and measure the final volume.
  6. Determine the final concentration of gold and citrate.

Figures

  • Spectrum from UV-VIS of 50x Diluted Citrate-AuNP Solution

Matt Hartings In the future, your spectra are going to be much easier to read if they only have lines (and no symbols).

Calculations from Part 2

  • The absorbance of the citrate-AuNP solution was determined by first determining the absorbance of a blank sample. The absorbance of the citrate-AuNP solution was correct by subtracting the absorbance of the blank sample.
  • In order to determine the molar absorptivity, ε, this reference was used. The peak appeared at 520 nm on the UV-VIS spectrum with a corresponding absorbance of 0.02. Using the ratio, Aspr/A450, it was determined that the nanoparticle diameter was 12 nm. This diameter is associated with a molar absorptivity of 1.09x108 M-1cm-1 as stated in the reference.
  • Using Beer's Law, A = εbc, the concentration of the diluted solution was calculated to be 1.83x10-10 M.
  • The concentration of gold in the original solution was calculated to be 1.97x10-9 M.

Observations

  • The final volume of Citrate-AuNP solution was 31.0 ml.

Matt Hartings based on this final volume (and initial concentration) what is your concentration of gold?

  • The progression of color change in Part 2 was light purple → dark purple → magenta → burgundy → deep red.
  • The final color of the BSA-AuNP solution was dark purple.
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