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The Effect of Temperature on the Aggregation of Colloidal Gold

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Shannon Cattie. The Effect of Temperature on the Aggregation of Colloidal Gold. Problem. How does temperature affect the rate of aggregation of colloidal gold?. Background Information. What is Colloidal Gold? Binary liquid mixture, containing gold nanoparticles

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Presentation Transcript
  • How does temperature affect the rate of aggregation of colloidal gold?
background information
Background Information
  • What is Colloidal Gold?
    • Binary liquid mixture, containing gold nanoparticles
    • Can be ingested orally to treat arthritis, hypertension, skin conditions, heart rhythm, depression, inflammation, circulation, pain and stress relief, nerve complaints, and act as an IQ booster
  • History of Colloidal Gold
    • Appearance in the Old Testament of the Bible (Exodus 32)
      • Moses makes a make-shift colloidal gold to cure the impatience and disobedience of the nation of Israel
    • Alexandria, Egypt
      • Alchemists discussed the Elixir of Life
      • 16th century: alchemist, Paracelsus, founded the school of iatrochemistry, the chemistry of medicines - beginning of modern pharmacology
    • Ancient Rome
      • Used to stain glass a deep red
    • Used for photography in 1842 in the process of crysotype
background information1
Background Information
  • Nanotechnology
    • Deals with processes that take place on the nanometer scale, which is one billionth of a meter.
    • Properties of metals are different on the Nano scale than in bulk.
      • Gold in bulk is a yellowish color, but gold’s nanoparticles are a wine-red
  • Aggregation
    • The formation of aggregates causing a change in color
    • For the most part, irreversible
    • An aggregate is a group of particles which are held together; they can be held together in any way
background information2
Background Information
  • Why add Salt to Aggregate Colloidal Gold?
    • Gold particles in colloidal solutions are negatively charged, so they repel each other. They cannot clump together.
    • Salt shields negative charges, causing clumping
  • Why does Colloidal Gold turn Blue after Aggregation?
    • Because of the change in the light spectra
  • Salt (NaCl)
    • Suppose to lower the temperature in which aggregation occurs
    • Enhances aggregation
  • If the temperature of colloidal gold is raised, then the particles of the colloidal gold will aggregate more readily than those at lower temperatures.
  • Journal
  • Pen
  • Aluminum foil
  • Refrigerator
  • Thermometer
  • A micro pipette
  • SpectroVis
  • Logger Pro
  • 10mL graduated cylinder
  • Paper towels

To make the colloidal gold

For each trial

A cuvette and cap

1000 μLof 1 M sodium chloride solution

3mL of colloidal gold

100μL of the solution

  • 20 mL of 1mM hydrogen tetrachloroaurate solution
  • Distilled water
  • 2mL of 1% trisodium citrate solution
  • Ahot plate
  • An Erlenmeyer flask
  • Graduated cylinder
  • Crucible tongs
procedure making the colloidal gold
Procedure – Making the Colloidal Gold

Make the Colloidal Gold

  • Measure 20 mL of 1mM hydrogen tetrachloroaurate solution in a graduated cylinder
  • Pour the 20 mL of 1mM hydrogen tetrachloroaurate solution into a 250 mL Erlenmeyer Flask
  • Add distilled water to the 200 mL mark on the Erlenmeyer flask
  • Place the Erlenmeyer flask onto a hot plate and turn the hot plate on a medium-high setting
  • Bring to a gentle boiling
  • Measure 2mL of 1% trisodium citrate solution using a 10 mL graduated cylinder
  • Add the 2mL of 1% trisodium citrate solution to the boiling solution in the Erlenmeyer flask
  • Continue heating the solution at a gentle boil for about 10 minutes until the solution is stable at a ruby or wine-red color and no longer changes color
  • After the color stabilizes, remove the Erlenmeyer flask from the hot plate and allow to cool
  • Add distilled water until the solution reaches 200 mL again
procedure testing the aggregation
Procedure – Testing the Aggregation
  • Begin by hooking up the spectrometer to the computer and opening Logger Pro
  • Measure 3 mL of Colloidal gold into a 10 mL graduated cylinder
  • Pour it into a cuvette
  • Cap the cuvette, wipe the sides of excess liquid, and place into the spectrometer
  • Locate the peak of absorption on the graph and record
  • Heat colloidal gold to 30°C by using a hot plate, let sit for the day and accumulate to room temperature (10°C), or place in refrigerator and cool to 10°C
procedure testing the aggregation1
Procedure – Testing the Aggregation

7. Collect the location of the peak of absorption on each graph after following this procedure:

  • Add the colloidal gold to the cuvette
  • Measure 100 microliters of sodium chloride solution using a micropipette
  • Add the 100 microliters of sodium chloride solution into the cuvette
  • Shake the cuvette once, and let sit for approximately 20 seconds
  • Place into Spectro Vis
  • Collect data
  • Repeat ten times
  • Independent variable: Sodium chloride solution
  • Dependent variable: Aggregation ratE
  • Control: Room temperature
  • Constants: Colloidal gold and amount of sodium chloride solution added
  • The data received showed all three temperatures aggregated similarly.
  • The hypothesis was rejected at the temperatures tested.
  • Further testing would be needed to conclude whether higher temperatures of colloidal gold increase the rate of aggregation.

Importance of this experiment:

  • Pertains much to recent scientific discoveries about nanotechnology
  • Nanotechnologists are testing the ability of colloidal gold to target cancer tumors.
possible errors and improvements
Possible Errors and Improvements

Possible Errors:

  • The testing taking place on different days
    • Slight temperature, humidity, and weather change
  • Change in temperature as the trials were being done
    • Temperature was not monitored after being placed in the cuvette
    • Solution could have accumulated to room-temperature without acknowledgement, although efforts were made to work quickly in order to manage this temperature change.
  • Sodium chloride solution not beginning at the same temperature as the colloidal gold

Improvements to this experiment:

  • Make the sodium chloride solution the same temperature as the colloidal gold, removing any difference in temperature between what was recorded
  • Monitor the solution temperature during procedure
works cited
Works Cited
  • Aslan, K., Lakowicz, J. R., & Geddes, C. D. (2004, Winter/Spring).
  • Nanogold-plasmon-resonance-based glucose sensing. Retrieved from
  • Colloidal Gold [Medical treatments using colloidal gold]. (1971). Retrieved from
  • CytImmune Sciences. (2011). What is Colloidal Gold? Retrieved from
  • go.cfm?do=Page.View&pid=15
  • Goldman, M. V. (n.d.). Absorption Spectra. In Absorption Spectra. Retrieved from Colorado Commission
  • on Higher Education and the National Science Foundation website:
  • physics/2000/quantumzone/fraunhofer.html
  • Retrieved from
  • Malvern Instruments Ltd. (2011). Colloidal Aggregation. Retrieved from
  • NANOYOU. (2011, July/August). Experiment with colorimetric gold nanosensors - Teacher guide (age
  • 11-13) [A Teacher's guide for experiments with colloidal gold]. Retrieved from
  • experiment-with-colorimetric-gold-nanosensors-teacher-guide-age-1113
  • Otwinowski, J. (2007, August 26). Temperature Induced Aggregation of Colloids [Journal testing the
  • effects of temperature on aggregation of colloids]. Retrieved from
  • ~pschall/People/Alumni/Thesis_JakubOtwinowski.pdf
  • Science In Motion. (2010). #24 Study of Colloidal Gold Solution. Retrieved from
  • Solomatin, S. V., Bronich, T. K., Eisenberg, A., Kabanov, V. A., & Kabanov, A. (2004, February 17).
  • Colloidal Stability of Aqueous Dispersions of Block Ionomer Complexes:  Effects of
  • Temperature and Salt [The effects temperature has on colloidal gold]. Retrieved from
  • database.
  • Space Today Online. (2003). Understanding Space Technology Spectrometers . Retrieved from
  • The Physics Classroom. (1996-2012). Color and Vision. Retrieved from comPADRE website:
  • Utopia Silver Supplements. (2005). The First Spiritual Recipe by The Great Physician [The history of
  • Colloidal Gold]. Retrieved from