User:Michael F. Nagle/Notebook/Chem 571/2012/10/31

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Objectives Obtain UV/Vis spectra for Au/Lysozyme samples with varying mole ratios. Purify ADA from E. Coli Procedure Au/Lysozyme samples prepared last Wednesday were analyzed by UV/Vis using disposable plastic cuvettes. The instrument held a blank cuvette of water, which was automatically subtracted from the spectra of the Au/Lysozyme. Samples from 134-140 showed variation in the background. In order to determine whether this was due to Lysozyme or variation in cuvettes, these trials were repeated using the same quartz cuvette. A blank of water was run using the same cuvette and subtracted from each spectra manually. Puja Moody purified ADA from E. Coli grown last week Data Discussion In the abs. vs mole ratio plot for the first round, done using plastic cuvettes, a jagged line is seen from 134-140. A significant change in backgrounds is seem on the wavelength vs. absorbance graph. Because of this, we analyzed these samples again using quartz cuvettes. Starting at 100, an increasing amount of AuNPs appear in solution. This peaks at 140 before decining to near-zero at 170. This indicates that the optimal mole ratio for AuNPs in solution is 140 and that they start to go into fibers at higher mole ratios.