b'Spectroscopic and Electrochemical Characterization of Iron (III) Oxide Based Electrodes for Photoelectrochemical CellsDanielle B. McKay Sponsor: Dr. Linda De La GarzaIron (III) Oxide, Fe2O3, an abundant and stable semiconductor, has become increasingly studied over the years in photoelectrochemical cells because of its ability to convert energy in the visible electromagnetic spectrum and to split water to produce hydrogen gas. Nanoparticulate solutions of Fe2O3 were prepared using the hydrolysis reaction of iron (III) ions. Solutions were concentrated and applied onto conductive indium tin oxide (ITO) slides using a dip coating method. To increase the photocurrent production and improve the fast recombination rates of Fe2O3, the nanoparticulate films will be further modified with small molecules such as dopamine and 3,4-dihydroxyphenylacetic acid. The films will be characterized and compared using spectroscopic and electrochemical techniques.Purification of Mutant Cytochrome c Expressed in E. coli for Fluorescent LabellingGrant T. McReadyAdviser: Dr. Yakov WoldmanThe goal of the project is to produce mutated cytochrome c protein with one lysine replaced by cysteine. The mutated protein will then be modified with cysteine-specific fluorescent label and used for detection of reactive oxygen species produced by cells. The plasmid containing mutated cytochrome c gene and E. coli transformed with this plasmid were produced in previous work. The current project involves expression and purification of the mutated cytochrome c from this E. coli. Transformed E. coli produces this protein which appears as a bright pink. Starting with frozen stock, 3 mL culture was grown to inoculate 1 L culture containing standard medium and carbenicillin, an antibiotic, to select for cells harboring the plasmid. These cells were collected, resuspended in lysis buffer and disrupted with glass beads. Centrifugation was used to remove the cell debris. The centrifugation is repeated with the addition of ammonium sulfate to salt-out unwanted proteins. The supernatant is subjected to ion-exchange chromatography and the target protein was eluted by an increasing concentration of sodium chloride. The purity of the collected fractions was checked through spectrophotometry and gel electrophoresis. The results show that mutated cytochrome c is stable and can be used for further modification.19'