User:Michael F. Nagle/Notebook/Chem 571/2012/09/04: Difference between revisions

From OpenWetWare
Jump to navigationJump to search
No edit summary
(20 intermediate revisions by 2 users not shown)
Line 7: Line 7:
<!-- ##### DO NOT edit above this line unless you know what you are doing. ##### -->
<!-- ##### DO NOT edit above this line unless you know what you are doing. ##### -->
==Objective==
==Objective==
* Using UV/Vis, find which mole ratios of [[AU_Biomaterials_Design_Lab:Materials/HAuCl4|HAuCl<sub>4</sub>]] to [[AU_Biomaterials_Design_Lab:Materials/BSA|BSA]] result in the most [[AU_Biomaterials_Design_Lab:Materials/BSA|BSA]] unfolding and formation of gold nanoparticles.
* Using UV/Vis, find optimal mole ratio of [[AU_Biomaterials_Design_Lab:Materials/HAuCl4|HAuCl<sub>4</sub>]] to [[AU_Biomaterials_Design_Lab:Materials/BSA|BSA]] for nucleation of gold nanoparticles in solution.
*Make Tris stock solutions and do serial dilution with [[AU_Biomaterials_Design_Lab:Materials/HAuCl4|HAuCl<sub>4</sub>]] and [[AU_Biomaterials_Design_Lab:Materials/BSA|BSA]] fibers in Tris buffer
* Prepare .1M Tris buffer at pH's of 8 and 10 to be added, at a wide range of concentrations, to solutions with Au/BSA fibers
** These solutions [[User:Michael_F._Nagle/Notebook/Chem_571/2012/09/05|will be analyzed via UV/Vis]] to determine the optimal pH and concentration of buffer for resuspension of fibers
 
==Procedure==
==Procedure==
#UV/Vis
*UV/Vis
##1mL of each solution with a varying mole ratios of [[AU_Biomaterials_Design_Lab:Materials/HAuCl4|HAuCl<sub>4</sub>]] and [[AU_Biomaterials_Design_Lab:Materials/BSA|BSA]] was inserted into a cuvette, which went into a UV/Vis Spectroscoper
**.1mL of each Au/BSA solution was inserted into a quartz cuvette, which went into a Shimadzu UV-2550 Spectrophotometer.
##Spectra were obtained and peaks for gold nanoparticles were identified at the 520nm range.
***These are not the same solutions prepared [[User:Michael_F._Nagle/Notebook/Chem_571/2012/08/29|8/29]], as the HAuCl<sub>4</sub> did not react, perhaps due to contamination from using a metal spatula that was not wrapped in parafilm. The solutions used here were prepared by [[User:Abigail_E._Miller|Dr. Miller]]
##Cuvette was cleaned between each spectra, and the same cuvette was used each time
**Cuvette was cleaned between each spectra and the same cuvette was used each time
#Tris buffer serial dilution
*Tris buffer serial dilution
## .1M solution of Tris was needed to begin serial dilutions.
** After being analyzed via UV/Vis, all HAuCl<sub>4</sub> and BSA solutions were centrifuged. The fibers became stuck along the side of the tubes and fluid was dumped.
### .1M Tris * .1L = .01mol
** .1M solution of Tris was prepared at pH's of 8 and 10 by [[User:Puja_Mody/Notebook/Chem_571:_Gold_Nanoparticles/2012/09/04|Puja Mody]]
### .01mol Tris * 121.14g/1mol = 1.21g Tris
** 9mL H<sub>2</sub>O was added to each tube. A serial dilution was completed using Tris buffer at pH of 8.
### Stock solution of Tris was made at pH 8 and 10.
** 1mL Tris stock was added to the first tube. 1mL from this tube was moved to the next tube, and so on for the 12 remaining tubes with fibers.
#### 1.21g Tris was added to each tube, with 85mL H<sub>2</sub>O
 
#### HCl was added dropwise until the pH changed to 8 and 10 in each tube, as indicated by a pH meter. 9mL HCl was added for pH=8 and 2mL was used for ph=10.
#### Sufficient water was added to leave the final volume of the solution at 100mL.
## 1mL was taken from the tube with a pipette and moved to the next tube. 1mL from this tube was moved to the next tube, and so on until all get some amount of Tris.
## 9mL H<sub>2</sub>O was put in the first tube to receive 1mL Tris from the stock solution.
## A serial dilution was repeated with H<sub>2</sub>O rather than Tris.
## Test tubes were wrapped and heated at at 80°C for 4 hours.
==Data==
==Data==
Image:BSA_AuNP_Uv-Vis.xlsx
Data for mole ratios from 130-140 was lost. This is because all spectra were saved as data print tables once trials were complete, and the spectra from 130-140 were not double clicked on before "Save" was clicked, and so other spectra were saved in their place. They could not be retrieved since the .spc files were not backed up.
==Conclusions==
[[Image:AuBSA1.png]]
* Concentrations of 128-134 should be retested because a significant drop in absorbancy was observed between these values and 120 and 138. Between the mole concentrations of 120 and 128, and 134-138, a significant change in peak height in seen. This indicates a difference in the amount of gold nanoparticles in solution. The range of 128-134 should be tested again because all other concentrations, higher and lower, have much higher peaks.  
 
*Dissolution of fibers in Tris should be tested at pH's 8 and 10 because Tris's optimal range is 7-9. Previous experiments used a pH of 10, which should also be tested so these can be replicated.
==Discussion==
* A significant drop in absorbance is seen between mole ratios 120 and 128. This indicates that this may be the point where gold nanoparticles stop going into solution and are only in fibers. However, research by Bakshi, et. al.<sup>1</sup>, indicates that the optimal mole ratio is from 132-134. More trials are needed to determine where the optimal range is.
*Dissolution of fibers in Tris should be tested at pH's 8 and 10 because Tris's optimal range is 7-9. We will also replicate previous experiments that used a pH of 10.


==References==
Bakshi, M.S.; Kaur, H.; Khullar, P.; Banipal, T. S.l; Kaur, G.; Singh, N. Protein Films of Bovine Serum Albumen Conjugated Gold Nanoparticles: A Synthetic Route from Bioconjugated Nanoparticles to Biodegradable Protein Films.<i> J. Phys. Chem.</i> C, 2011, 115 (7), pp 2982–2992
<!-- ##### DO NOT edit below this line unless you know what you are doing. ##### -->
<!-- ##### DO NOT edit below this line unless you know what you are doing. ##### -->
|}
|}


__NOTOC__
__NOTOC__

Revision as of 20:37, 6 December 2012

Project name <html><img src="/images/9/94/Report.png" border="0" /></html> Main project page
<html><img src="/images/c/c3/Resultset_previous.png" border="0" /></html>Previous entry<html>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</html>Next entry<html><img src="/images/5/5c/Resultset_next.png" border="0" /></html>

Objective

  • Using UV/Vis, find optimal mole ratio of HAuCl4 to BSA for nucleation of gold nanoparticles in solution.
  • Prepare .1M Tris buffer at pH's of 8 and 10 to be added, at a wide range of concentrations, to solutions with Au/BSA fibers

Procedure

  • UV/Vis
    • .1mL of each Au/BSA solution was inserted into a quartz cuvette, which went into a Shimadzu UV-2550 Spectrophotometer.
      • These are not the same solutions prepared 8/29, as the HAuCl4 did not react, perhaps due to contamination from using a metal spatula that was not wrapped in parafilm. The solutions used here were prepared by Dr. Miller
    • Cuvette was cleaned between each spectra and the same cuvette was used each time
  • Tris buffer serial dilution
    • After being analyzed via UV/Vis, all HAuCl4 and BSA solutions were centrifuged. The fibers became stuck along the side of the tubes and fluid was dumped.
    • .1M solution of Tris was prepared at pH's of 8 and 10 by Puja Mody
    • 9mL H2O was added to each tube. A serial dilution was completed using Tris buffer at pH of 8.
    • 1mL Tris stock was added to the first tube. 1mL from this tube was moved to the next tube, and so on for the 12 remaining tubes with fibers.

Data

Data for mole ratios from 130-140 was lost. This is because all spectra were saved as data print tables once trials were complete, and the spectra from 130-140 were not double clicked on before "Save" was clicked, and so other spectra were saved in their place. They could not be retrieved since the .spc files were not backed up.

Discussion

  • A significant drop in absorbance is seen between mole ratios 120 and 128. This indicates that this may be the point where gold nanoparticles stop going into solution and are only in fibers. However, research by Bakshi, et. al.1, indicates that the optimal mole ratio is from 132-134. More trials are needed to determine where the optimal range is.
  • Dissolution of fibers in Tris should be tested at pH's 8 and 10 because Tris's optimal range is 7-9. We will also replicate previous experiments that used a pH of 10.

References

Bakshi, M.S.; Kaur, H.; Khullar, P.; Banipal, T. S.l; Kaur, G.; Singh, N. Protein Films of Bovine Serum Albumen Conjugated Gold Nanoparticles: A Synthetic Route from Bioconjugated Nanoparticles to Biodegradable Protein Films. J. Phys. Chem. C, 2011, 115 (7), pp 2982–2992


Retrieved from "https://openwetware.org/mediawiki/index.php?title=User:Michael_F._Nagle/Notebook/Chem_571/2012/09/04&oldid=662679"