User:Melvin Colorado Escobar/Notebook/chem 472/2016/02/23

Biomaterials Design Lab

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Objective Make new red and purple gold nanoparticles to analyze with UV Vis. Make spring water for the plants Protocol We made new stock solutions of our red and purple AuNPs to test via UV-Vis for a calibration curve. We need to varify that our calibration curve made on 02/03/2016 is accurate. According to that data, our purple nanoparticles absorbed the fastest, even though they are the largest nanoparticles. Since our red nanoparticles are smaller, it is expected that they would absorb faster. Since these results do not match what we would expect, the nanoparticle standard solutions for both red and purple were both made to reanalyze via UV Vis to verify that our results are correct. Stock Solutions 0.517g gold in 5 mL of water (1% solutions by molecular weight) .10.072 sodium citrate in 5mL of water Synthesis of Citrate AuNPs: Both solutions for the preparation of the red and purple AuNPs were made using the following: 1mL of HAuCl4 stock solution (1) was added to 90mL water (see below) in a 100mL volumetric flask. The solution was heated while stirring until it reached 90 degrees Celsius. 2mL of the sodium citrate stock solution (2) was added to the solution. The reaction caused the mixture to turn from clear, black, purple, then to red. Since we want one red and one purple AuNP solution, one of the solutions was stopped early when it was pruple, and the other was left to react until it turned red. Preparation of "Spring" Water The following was added to 500mL of water in a volumetric flask to create spring water for the synthesis of our gold nanoparticles starting tomorrow. 4.66mg NaCl 0.62mg MgSO4 0.75mg NaNO3 2.35mg CaCl2 Results Although the purple solution was stopped early, the solution kept reacting, creating more red nanoparticles. We are planning on repeating the synthesis tomorrow in hopes of creating purple AuNPs.