User:Helen L. Slucher/Notebook/CHEM 571/2013/08/28: Difference between revisions
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==Notes== | ==Notes== | ||
Citrate AuNP | |||
Peak Wavelength: 518 nm | |||
Absorbance at Peak: .612 | |||
In order to determine the concentration, the Absorbance at 450 is known. | |||
Abs (450): .389 | |||
Abs (518)/ Abs (450)= .612/ .389= 1.57 | |||
Using the data found [http://pubs.acs.org/doi/suppl/10.1021/ac0702084/suppl_file/ac0702084si20070321_014144.pdf here] the value of 1.57 resulted in 12 d/nm and a molar absorptivity of 1*10^8. | |||
Using Beer's law and the newly found value for molar absorptivity, the concentration was determined to be 3.57*10^-9M. | |||
<br>[[Image:Absorbtionvswavelength.png|right|]] | |||
Beer's Law gives an equation for the absorption of light and the properties of the solution. | |||
:<math>\ A=\epsilon bc </math> | |||
<br>A is absorbance. | |||
<br>ε is molar absorptivity with units of L mol<sup>-1</sup> cm<sup>-1</sup>. | |||
<br>b is the path length of the sample. | |||
<br>c is the concentration with units of mol L<sup>-1</sup>. | |||
<br>From the Absorption vs Wave Length Graph, the peak is at a wave length of 518nm and absorbance is 0.612. As the peak is at a wave length less than 520nm, table S-1 from the reference is used. | |||
<br>A<sub>450</sub>=0.389 | |||
<br>A<sub>518</sub>=0.612 | |||
<br>A<sub>518</sub>/A<sub>450</sub>=1.57 | |||
<br>From table S-1, d/nm=12 | |||
<br> d/nm is the diameter of the particle is nm. | |||
<br>ε<sub>450</sub>=1.09*10<sup>8</sup> M<sup>-1</sup>cm<sup>-1</sup> | |||
<br>To find the concentration, the following equation is used; c=A<sub>450</sub>/ε<sub>450</sub> | |||
<br>c=0.389/1.09*10<sup>8</sup>L mol<sup>-1</sup> cm<sup>-1</sup> | |||
<br>c=3.5688*10<sup>-9</sup> mol L<sup>-1</sup> | |||
==References== | ==References== | ||
[http://openwetware.org/wiki/User:Matt_Hartings/Notebook/AU_Biomaterials_Design_Lab/2013/08/28 Dr. Harting's AU Biomaterials Design Lab] | [http://openwetware.org/wiki/User:Matt_Hartings/Notebook/AU_Biomaterials_Design_Lab/2013/08/28 Dr. Harting's AU Biomaterials Design Lab] |
Revision as of 15:30, 16 September 2013
Project name | <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> |
OverviewSynthesize 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. BSA-Au Nanoparticles
Stock solutions made
Citrate-Au Nanoparticles
Stock solutions made
NotesCitrate AuNP Peak Wavelength: 518 nm Absorbance at Peak: .612 In order to determine the concentration, the Absorbance at 450 is known. Abs (450): .389 Abs (518)/ Abs (450)= .612/ .389= 1.57 Using the data found here the value of 1.57 resulted in 12 d/nm and a molar absorptivity of 1*10^8. Using Beer's law and the newly found value for molar absorptivity, the concentration was determined to be 3.57*10^-9M. Beer's Law gives an equation for the absorption of light and the properties of the solution.
References |