Transcript Kevin undergrad_poster_McNair

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
Introduction
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 Fe3O4 particles can switch their
magnetic field to attract the other particles and
aggregate and precipitate out of solution.
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.
Methods
Bio-Application
)))
Time, t
Fe3O4
• Sonicate iron pentacarbonyl for 3 hours
• Wash with solvent (e.g. double-distilled water,
acetone, or methanol)
Cys-Fe3O4
DI-Water
Iron Pentacarbonyl
Iron Magnetic
Nanoparticle
(1) Magnetic nanoparticles, functionalized
with cysteine improve the solubility and
performance characteristics for biomaterials
in aqueous & non-aqueous conditions.
(2) Different conditions such as sonication
time, temperature, and the concentration of
DL-Cysteine will affect the magnetic CysFe3O4 colloidal suspensions due to the
surface structure of Cys-Fe3O4.
• Two primary binding
groups
• Carboxyl (-COOH)
• Amine (-NH2)
• Covalent binding
DNA Binding Ability
DI-Water
Cys-Fe3O4
Complex
Iron Magnetic
Nanoparticle
• Add iron pentacarbonyl Fe(CO)5
• Inject DL-Cysteine into solution
• Sonicate for 3 hours
• Wash with solvent
• Let (magnetically) precipitate
Data Analysis
Transmission Electron Microscopy (TEM)
TEM
SEM
• Determine structure
• Magnetic core with shell
• View individual particle and clusters
• Determination of size and colloid stability
• Measure surface charges and the particle
mobility
Fourier-Transform Infrared Spectroscopy (FT-IR) &
Raman Spectroscopy
• Characterization of coated/uncoated particles
Structure of DNA
• Chemically bind Cys-Fe3O4 to glass
substrate
• Immobilize the enzyme on the Cys-Fe3O4
coated surface
• Get diagnostic reading from enzyme reaction
• Tilted image of dried particles (3D)
• Determine size (nm) and morphology
Dynamic Light Scattering & Zeta Potential (+/-, mV)
• 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
Biosensors
Scanning Electron Microscopy (SEM)
Hypothesis
Fe3O4
)))
Time, t
+
DL-Cysteine
Enzyme Immobilization
FT-IR
ACKNOWLEDGMENTS
Advisor : Dr. Patrick A. Johnson
Mentor: Joo Seob Lee
We acknowledge the financial support from the McNair Scholars Program at the
University of Wyoming