Each group needs:

• 20 ml gold colloid (have students synthesize these gold nanoparticles using supplies listed below and instructions in the Procedure section; alternatively: purchase the gold nanoparticles—see suggested source below, or ask for a small supply from your local university)
• Gatorade Ice^TM (colorless flavor), 2 drops
• pickle juice with little color, 2 drops
• Pedialyte^® (flavorless), 2 drops
• PowerAde^TM (any colorless flavor), 2 drops
• 4 1-dram glass vials (at https://www.sks-bottle.com/340c/fin11a.html or https://www.amazon.com/Glass-Vials-Dram-Pack-12/dp/B002JV6976)
• 4 disposable plastic pipets
• glass waste container with screw-top lid
• gloves and goggles for each student
• Thirsty for Gold Worksheet, one per student

Supplies for gold nanoparticle fabrication by teacher for the entire class:

• 20 ml of 1.0 mM HAuCl₄, gold (III) chloride hydrate; for example, part #244169-500 mg for $98 at www.sigmaaldrich.com. NOTE: To make 20 ml solution of 1.0 mM HAuCl₄, dissolve 7 mg of solid gold (III) chloride hydrate in distilled water.
• 2 ml of 38.8 mM Na₃C₆H₅O₇, sodium citrate anhydrous; for example, part #W302600-Sample K for $40 at www.sigmaaldrich.com. NOTE: to make 2 ml of 38.8 mM sodium citrate anhydrous, dissolve 14.86 mg of solid Na₃C₆H₅O₇ in 2 ml of distilled water.
• stirring hot plate
• magnetic stir bar
• distilled water, 50 ml (this is water for the above solution preparation and additions as solutions boil)
• (optional) refrigerator, for cooling solution, and fume hood

To purchase gold nanoparticles (or ask for a small supply from your local university biochemistry or chemistry programs):

• Get enough for 20 ml gold colloid per group
• Example source of gold colloid: part #752568 for $298 at www.sigmaaldrich.com. NOTE: It is much less expensive to source raw chemicals and make solutions, and raw materials last for multiple activities.