1 / 17

Optical Nanoparticle Trapping Sensor

Darryl Benally Team member: ChEng Graduate Student Christopher Killingsworth Supervisor: Professor Randy Bartels. Optical Nanoparticle Trapping Sensor. Outline. Project Goals Prior Research Current Progress Budget Plans for next semester. Project Goals.

Download Presentation

Optical Nanoparticle Trapping Sensor

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.


Presentation Transcript

  1. Darryl Benally Team member: ChEng Graduate Student Christopher Killingsworth Supervisor: Professor Randy Bartels Optical Nanoparticle Trapping Sensor

  2. Outline • Project Goals • Prior Research • Current Progress • Budget • Plans for next semester

  3. Project Goals • Pathogen detection of food borne illnesses at very low concentration • Detection time to less than 24 hours Scanning electron microscope image of E coli Image from National Institute of Allergy and Infectious Diseases • http://www3.niaid.nih.gov/topics/Biodefense • Related/Biodefense/PublicMedia/image_library.htm

  4. Project Goals Strategy of binding pathogens to gold nanoparticles • A dissolved sample containing pathogens (red dots). • Gold nanoparticles with attached anti-bodies (gold/blue dots) are added. • Nanoparticles will fill a large volume and attach to pathogens. • The attached pathogens to nanoparticles are selectively concentrated in the trap volume (broken line) for subsequent detection.[a]

  5. Collect Nanoparticles for Detection Gaussian Beam Shape Evanescent Field Decay FZ FX Polarizable Particle X Total Internal Reflection (TIR) Z Incident TM Radiation Reflected Radiation

  6. Collect Nanoparticles for Detection • Trapping force scales with r3 • Brownian motion scales with 1/r • Concept behind for selective concentration of different sized nanoparticles • As radius increases trapping forces increase and Brownian motion decreases • Nanoparticle in Rayleigh regime causing the particle to behave as an inducible point dipole • Brownian motion • Brownian motion • Trapping force • Trapping force

  7. Prior Research • Research done in past summer on developing techniques on making the gold nanoparticles and attaching anti-bodies

  8. Assignment to Project • Build Prism Mounts and Prism Holder • Theoretical Calculations for Particle Dynamics

  9. Coating Prism Mount • Coating the prism with gold • No mount commercially available 14 [mm] 10 [mm] 10 [mm]

  10. Using Prism for TIR Light Source for Absorption Spectrum • Using the prism dimension to cause Total Internal Reflection (TIR) • A light beam will enter on the sides and refracted to appropriate angles Gaussian Beam Shape • Particles will move into the center of the evanescent field • A second light source will be directed from the top to perform establish absorption spectrum • The detection of the gold nanoparticles will come from differential absorption spectroscopy Incident TM Radiation Reflected Radiation (Not to Scale)

  11. Prism Holder Design • The first design that was made • The idea was to bring the beam through the sides to cause TIR • The top piece used to securing place the prism sealing the sample • The opening for the second light source the differential absorption spectroscopy • However, prove to be unstable and difficult to mount • A second design was need

  12. Prism Holder Design 1 in • Second design • The holder can be placed within an optical mount Side view Corner View Top view

  13. Theoretical Calculations • These calculations are used to evaluate the particle dynamics in fluidic chamber • The theoretical calculations will help predict how far the particle will fall once under the optical forces • These predictions will help in determining how fast the fluid in the chamber will need to be

  14. Derivation of Differential Equation • Assuming uniform gradient force • Assuming laminar flow • Assuming gradient force is much greater than scattering forces Fdz z Coordinates Fdx Laminar Flow Velocity x Fg x distance Prism Gold Coated Surface

  15. Budget • Budgeted 50 dollars from ECE department • Have not spent any of this money • The Project is funded through the Infectious Disease Supercluster here at CSU

  16. Plans for Next Semester • Design and build new prism mount with more stability • Perform test and evaluate • Put together new setup for more sensitive detection using thermal modulation of nanoparticles

  17. Questions ?????????

More Related