Team:Concordia/Safety/SOP/Martin
Chemical Synthesis: Martin Method
*The safety information in the table above is based on the SDS for each chemical.
1. Cedarlane. SDS: Chloroauric Acid.
2. Sigma-Aldrich Corporation. SDS: Trisodium Citrate Dihydrate.
3. Sigma-Aldrich Corporation. SDS: Sodium Borohydride.
Used to synthesize gold nanoparticles ranging from 1-10nm
Protocol:
Perform all steps in FUME HOOD.
1. Measure 20 mL of distilled-deionized H2O (ddH20) into 50 mL graduated cylinder and pour into 125mL Erlenmeyer flask.
2. Keep some extra ddH2O on ice for later steps in a falcon tube.
3. Weigh out 1.96 mg (0.00196 g) of chloroauric acid trihydrate (HAuCl4*3 H2O) solid on a weigh-boat.
CAUTION: oxidizes quickly - do not expose to air for longer than required
Do NOT use metal scoopula - use plastic or wood to transfer the solid
LIGHT SENSITIVE - use for short duration under light conditions
Note: chloroauric acid is expensive - try not to be wasteful!
4. Using a micropipet, quickly add ~40 uL of the ddH2O from the flask to the crystals of chloroauric acid trihydrate on the weigh-boat. This should dissolve the solid to generate a yellow mixture on the weigh-boat. Then use the micropipette to transfer the yellow liquid to a 1.5 mL microfuge tube.
By avoiding transfer of the solid form of HAuCl4, the possibility of loss of sample is lessened. Transfer as a liquid is preferable. Seal the tube rapidly to limit air exposure of the chemical.
5. Micropipet the HAuCl4 solution directly into the flask and seal the opening with aluminum foil.
6. Add stir bar to flask and mix on plate to allow the solid HAuCl4 to dissolve.
Nanoparticle synthesis occurs at this step.
Having the flask opening covered with aluminum foil prevents the escape of fumes from the synthesis reaction.
7. Weigh out 1.47 mg (0.00147 g) of trisodium citrate dihydrate solid.
8. Add the trisodium citrate dihydrate to the mixture in the flask with stirring.
9. On ice, prepare 0.1 M sodium borohydride (NaBH4) solution.
Pipet 0.65 mL (650 uL) of cold ddH2O into a 1.5mL microfuge tube kept on ice.
Weigh out 2.46 mg (0.00246 g) of NaBH4.
Put the measured NaBH4 into the microfuge tube containing ddH2O and resuspend by pipetting until the solid is fully dissolved (keep on ice throughout).
10. Add 0.6 mL (600 uL) of the cold 0.1 M NaBH4 solution into the mixture in the Erlenmeyer flask while stirring vigorously on the stir plate. - NOTE: the solution should turn dark red immediately - indicating particle formation.
11. The solution is then tested for presence of nanoparticles using UV spectrophotometry
Expected absorbance peak between 510-525 nm.
12. Once nanoparticles are confirmed in solution:
Weigh out 0.15 g of L-cysteine solid.
Add the L-cysteine to the nanoparticle solution with stirring for ~10 min.
13. Collect nanoparticles by pelleting using centrifugation at 1,000 RPM at room temperature for 50 minutes.
14. Store the solution in 4°C fridge.
Source: Jiang, N., Yang, X-Y., Ying, G-L., Shen, L., Liu, J., Geng, W., Dai, L-J., Liu, S-Y., Cao, J., Tian, G., Sun, T-L., Li, S-P., and Su, B-L. (2015) “Self-repairing”nanoshell for cell protection. Chem. Sci., 6:486-491. Retrieved from http://pubs.rsc.org/en/Content/ArticleLanding/2015/SC/c4sc02638a#!divAbstract
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