User:Moira M. Esson/Notebook/CHEM-571/2013/10/23

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Objectives Run UV-vis on the 20 protein-Au nanoparticle samples prepared on 10/22/2013. Synthesize new HRP-AuNP solutions and Myoglobin-AuNP solutions for future catalytic activity testing. HRP-AuNP and Myoglobin-AuNP The protein-AuNP solutions prepared on 10/22/2013 did not produce fibers. As such, new protein-AuNP solutions with increased ratios of protein-AuNP were prepared in order to determine the optimal concentration of Au to protein to synthesize fibers. The general protocol for the synthesis of HRP-AuNP and Pepsin-AuNP follows the general protocol for the preparation of protein wrapped Au-NPs described on 08/28/2013. 5mL of each solution was prepared. Table 1. Stock solutions used in the preparation of Protein-AuNP solutions Concentration HRP Day 2(M) Concentration Gold Stock (M) Myoglobin (M) 0.0000015 0.0025 0.0000165 Table 2. Preparation of HRP-AuNP solutions Ratio Amount of gold added (mL) Concentration HRP (M) Volume HRP (mL) Volume H2O added (mL) 230 0.5 1.08696E-06 3.623188406 0.876811594 250 0.5 0.000001 3.333333333 1.166666667 270 0.5 9.25926E-07 3.086419753 1.413580247 290 0.5 8.62069E-07 2.873563218 1.626436782 310 0.5 8.06452E-07 2.688172043 1.811827957 330 0.5 7.57576E-07 2.525252525 1.974747475 350 0.5 7.14286E-07 2.380952381 2.119047619 370 0.5 6.75676E-07 2.252252252 2.247747748 390 0.5 6.41026E-07 2.136752137 2.363247863 410 0.5 6.09756E-07 2.032520325 2.467479675 Table 3. Preparation of Myoglobin-AuNPs Ratio Amount of gold added (mL) Concentration Myoglobin (M) Volume of myogloblin(mL) Volume Water Myoglobin(mL) 30 0.5 8.33333E-06 2.525252525 1.974747475 50 0.5 0.000005 1.515151515 2.984848485 70 0.5 3.57143E-06 1.082251082 3.417748918 90 0.5 2.77778E-06 0.841750842 3.658249158 110 0.5 2.27273E-06 0.688705234 3.811294766 130 0.5 1.92308E-06 0.582750583 3.917249417 150 0.5 1.66667E-06 0.505050505 3.994949495 170 0.5 1.47059E-06 0.445632799 4.054367201 190 0.5 1.31579E-06 0.398724083 4.101275917 210 1.19048E-06 0.360750361 4.139249639 UV/vis of Pepsin-AuNP and HRP-AuNP General Protocol: Place 1mL of each ratio in an 1.5mL eppendorf tube. Centrifuge at maximum speed for 30 minutes. Take a UV-Vis spectrum of each sample from 200nm to 800nm. After taking the spectrum, store the sample in a fresh eppy tube in an upright position. Figure 1. Corrected Absorbance spectra of pepsin-AuNPs Both 30:1 and 70:1 pepsin-AuNP had an absorbance peak at 518nm. Notes The remaining UV/vis samples will be run during the next lab period. Although neither the HRP or the pepsin solutions formed fibers, a black residue and color change(see figure 2) was observed for the pepsin solutions. The black residue will be tested in the future for identification.