IGEM:American University/2009/Notebook/Chem 672/2017/01/31

iGEM Project name 1

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Protein templated CdS, ZnS and ZnSe Quantum Dots Proposal We will attempt to synthesize various sizes of quantum dots using BSA, Myoglobin and Lysozyme at pH's 4-10. The quantum dots that will be synthesized will be CdS, ZnS and ZnSe, which have been synthesized using various other templates. At pH 10 and above it has been reported that quantum dots do not form, it has also been shown from studies done last semester that nanoparticles in general do not form in protein cages above pH 10. BSA, myoglobin and lysozyme were chosen as the protein templates because of the research done last semester on their ability to synthesize gold and silver nanoparticles. Procedure The following procedures vary for each type of quantum dot being synthesized, but will not change for each type of protein template being used. CdS synthesis A 5 mL reaction mixture was prepared with 1.0 M thioacetic acid added dropwise to the protein solution (BSA-3.125 uM, myoglobin-12.5 uM, lysozyme-12.5 uM) with 1.0 mM cadmium acetate and 75 mM aqueous ammonium at various pHs (4-12). The solution was stirred overnight at room temperature and analyzed via the Shimadzu UV-2550 UV-Vis spectrometer and the Perkin Elmer LS 55 fluorescence spectrometer. ZnSe Synthesis Selenourea was prepared at 100 mM in deionized water with a minimal amount of ethanol to aid in dissolution. The selenourea solution was prepared just before being added to the solution and was the last to be added. A 5 mL reaction mixture was prepared by adding 5 mM selenourea solution dropwise to the protein solution (BSA-3.125 uM, myoglobin-12.5 uM, lysozyme-12.5 uM) with 1 mM zinc acetate and 40 mM ammonium acetate at various pHs (4-12). The solution was stirred overnight at room temperature and analyzed via the Shimadzu UV-2550 UV-Vis spectrometer and the Perkin Elmer LS 55 fluorescence spectrometer. ZnS Synthesis A 5 mL reaction mixture was prepared by adding 1 mL of 2 mM Na2S dropwise to a reaction solution consisting of 1 uL of 1 mM ZnCl2 in 20 mM Tris-HCl, pH 7.0. The volume was adjusted to 4 mL with 20 mM Tris-HCl, pH 7. pH was adjusted using 10 mM ammonium hydroxide or 1 mM HCl. The reaction mixture was stirred vigorously at room temperature for 5-10 minutes before being transferred to an incubator at 37oC and aged for 1-7 days. The solution was analyzed via the Shimadzu UV-2550 UV-Vis spectrometer and the Perkin Elmer LS 55 fluorescence spectrometer. Note The procedures shown above are experimental procedures which are up for change and modification as seen fit based on results.