Introduction

1. The study of cysteine molecule coated magnetic Fe3O4 nanoparticles via sonochemical method for bio-applications Kevin J. Schilling, Joo Seob Lee, and Patrick A. Johnson Biointerfacial Engineering Laboratory Department of Chemical & Petroleum Engineering Fe3O4 Methods Introduction Bio-Application In past years, magnetic Fe3O4 nanoparticles have been a tremendous asset to the biomaterial field and as such there has been a high desire to synthesize and optimize these nanoparticles. These magnetic Fe3O4 particles are very diverse. They can be used as catalysts, be used in drug delivery, or aid in magnetic hyperthermia treatment. These nanostructured particles being created have super paramagnetic behaviors; these magnets can flip their magnetic direction due to either temperature or the presence of a magnetic field. In contrast, magnetic Fe3O4particles can switch their magnetic field to attract the other particles and aggregate and precipitate out of solution. Enzyme Immobilization ) ) ) Time, t Fe3O4 • Two primary binding groups • Carboxyl (-COOH) • Amine (-NH2) • Covalent binding • Sonicate iron pentacarbonyl for 3 hours • Wash with solvent (e.g. double-distilled water, acetone, or methanol) ) ) ) Time, t DI-Water Iron Pentacarbonyl Iron Magnetic Nanoparticle + DNA Binding Ability DI-Water • Double helix structure in DNA • Phosphate groups on 3’ and 5’ ends of sugar backbone • Amine binding • Nitrogen attack phosphate • Carboxyl binding • Carboxyl group (C=O) attack phosphate • Possible addition of acid DL-Cysteine Cys-Fe3O4 Complex Iron Magnetic Nanoparticle Cys-Fe3O4 • Add iron pentacarbonyl Fe(CO)5 • Inject DL-Cysteine into solution • Sonicate for 3 hours • Wash with solvent • Let (magnetically) precipitate Problem This study will examine cysteine coated magnetic nanoparticles (Cys-Fe3O4) fabricated with sonochemical approaches, using (1) metal salt mixtures (e.g., Fe3+, Fe2+) and (2) iron pentacarbonyl (Fe(CO)5) in conjunction with a small molecule surfactant. A comparison of the two methods in order to create more uniform dispersion will be performed in order to prevent cysteine-cysteine interactions on the surface of Cys-Fe3O4. Data Analysis Transmission Electron Microscopy (TEM) TEM SEM Structure of DNA • Determine structure • Magnetic core with shell • View individual particle and clusters Biosensors • Chemically bind Cys-Fe3O4 to glass substrate • Immobilize the enzyme on the Cys-Fe3O4coated surface • Get diagnostic reading from enzyme reaction Scanning Electron Microscopy (SEM) Hypothesis • Tilted image of dried particles (3D) • Determine size (nm) and morphology • Magnetic nanoparticles, functionalized with cysteine improve the solubility and performance characteristics for biomaterials in aqueous & non-aqueous conditions. • Different conditions such as sonication time, temperature, and the concentration of DL-Cysteine will affect the magnetic Cys-Fe3O4 colloidal suspensions due to the surface structure of Cys-Fe3O4. Dynamic Light Scattering & Zeta Potential (+/-, mV) FT-IR • Determination of size and colloid stability • Measure surface charges and the particle mobility Fourier-Transform Infrared Spectroscopy (FT-IR) & Raman Spectroscopy ACKNOWLEDGMENTS Advisor : Dr. Patrick A. Johnson Mentor: Joo Seob Lee Weacknowledge the financial support from the McNair Scholars Program at the University of Wyoming • Characterization of coated/uncoated particles