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Topic

Label-Free Studies of Single Biological Nanoparticles Using Optical Nanotweezers

Department of Electrical and Computer Engineering

Date & location

• Wednesday, June 19, 2024

• 12:00 P.M.

• Engineering Computer Science Building

• Room 130

Reviewers

Supervisory Committee

• Dr. Reuven Gordon, Department of Electrical and Computer Engineering, ·¬ÇÑÉçÇø (Supervisor)

• Dr. Levi Smith, Department of Electrical and Computer Engineering, UVic (Member) 

External Examiner

• Dr. Peter Loock, Department of Chemistry, ·¬ÇÑÉçÇø 

Chair of Oral Examination

• Dr. Kristin Semmens, Department of History, UVic

   

Abstract

This thesis has two parts. In the first, we demonstrated tracking and imaging of single proteins without a fluorescent label or tether, well below the previously achieved smallest protein. This result made use of interference effects similar to interferometric scattering microscopy, with additional interference enhancement from the enhanced electromagnetic field. We use the tracking to obtain a single proteins velocity and size the protein. In the second part, we explored the use of optical scattering from an unlabelled. single extracellular vesicle to be used for cancer diagnostics. We trained a 1D-convolutional neural network using the transmission signal of an extracellular vesicle trapped in a double nanohole. We achieved a greater than 90% accuracy in classifying an extracellular vesicle with its parent cell. Three different parent cells were used, MCF10A (non-malignant), MCF7 (non-invasive, cancerous), and MDA-MB-231 (invasive, cancerous).