User:Madeleine Y. Bee/Notebook/Single Molecule Fluorescence/2013/07/19

AuNP Synthesis and Absorbance Spectra

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July 18, 2013 Procedures: Gold Nanoparticle Synthesis by Sodium Citrate Reduction Methods Desired gold nanoparticle size: approximately 10nm. First Procedure Adapted from Nonspecific and Thiol-Specific Binding of DNA to Gold Nanoparticles.<br.> Boil 50mL MilliQ water in a clean beaker Add 0.5 mL of HAuCl4 solution (1% w/v) 1% w/v = (0.01g in 1mL water) Follow with 1.75 mL of sodium citrate solution (1% w/v) Boil for about 10 minutes until solution color changes to bright red Replace water lost to evaporation during boiling If a higher concentration is desired, centrifuge at 14 000 rpm and resuspended in MilliQ water Absorbance Data Second Procedure Adapted from 4-(Dimethylamino)butyric Acid Labeling for Electrochemiluminescence Detection of Biological Substances by Increasing Sensitivity with Gold Nanoparticle Amplification.<br.> Bring 100 mL of solution containing 0.01 g of HAuCl4·3H2O to a boil Add 3 mL of 1% sodium citrate solution while stirring Boil solution for another 40 minutes Cool to room temperature Absorbance Data Original Procedure From Allison Alix on 05/10/2013.<br.> Stir and heat to boiling 20mL of 1mM HAuCl4 Add 2mL 1% sodium citrate Observe a purple to red color change Determine size and concentration of AuNP using UV-Vis Absorbance Data Solution too concentrated; will be diluted and measurements taken again tomorrow.