Event Details
Label-Free Single-Particle and Single-Protein Analysis Using Double Nanohole Optical Tweezers
Presenter: Tianyu Zhao
Supervisor:
Date: Fri, September 4, 2026
Time: 10:00:00 - 11:00:00
Place: Zoom - see below.
ABSTRACT
Location: Remote via Zoom
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https://zoom.us/j/97745041226?pwd=zPP50fkg8pKbnlOuPrJFu8KAGQ8qon.1
Meeting ID: 977 4504 1226
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Abstract:
Double nanohole (DNH) optical tweezers provide a label-free platform for trapping nanoscale biological objects while simultaneously monitoring their optical transmission signals in real time. In this seminar, I will present our recent work using DNH optical tweezers for the characterization of extracellular vesicles and individual proteins. First, I will discuss the classification of extracellular vesicles derived from different breast cancer cell lines using optical trapping signals combined with machine-learning methods, demonstrating that the time-dependent trapping signal contains information that can distinguish different EV populations. I will then present studies of single-protein conformational dynamics, where multi-state trapping signals are analyzed to reconstruct temperature-dependent free-energy landscapes. In addition, I will introduce a zero-power extrapolation approach for investigating protein–surface interactions near the nanoaperture and show how the observed interaction depends on protein charge. Finally, I will discuss conalbumin as an example of how biochemical changes such as iron binding can influence both surface interactions and conformational dynamics. Together, these studies demonstrate the potential of DNH optical tweezers as a versatile platform for label-free, real-time biophysical measurements at the single-particle and single-protein level.