College of Science

Seminar: Anna Bezryadina [UC San Diego]

[BIOPHYSICS SEMINAR] Optical manipulation of bacteria and plasmonic super-resolution microscopy

Jan 25, 2018 11:00 AM to Jan 25, 2018 12:00 PM at 8-241

In this talk I will focus on my recent research in developing optical tweezers for trapping, manipulating, and stretching clusters of cells. Highly focused light produces forces which can provide accurate control and manipulation of objects from 10 nm to over 100 µm. Using computer-generated holograms, differently shaped beams can be created to match the morphology of non-spherical microorganisms. The specially designed “tug-of-war” optical tweezers were applied to understand bacterial aggregation and biofilm formation, which may assist in developing new treatments for chronic infections and antibiotic-resistant bacteria.

Also, I will highlight the first demonstration of biological waveguides in biological suspensions (bacteria and human red blood cells), which guide light over long distances with almost negligible photodamage. Optical forces attract multiple cells along the beam without cells’ clustering and form several centimeters long biological “fiber”. This new discovery opens up promising new opportunities to engineer biological microchips and perform deep-tissue imaging and noninvasive medical treatments and diagnostics.

            Finally, I will talk about utilizing plasmonic effects to perform high-speed super-resolution imaging. By creating a plasmonic periodic nano-array, the sample can be structure illuminated beyond the traditional diffraction limit, leading to a unique path-enhanced resolution more than 3 times. With the localized plasmonic structure illumination microscopy (LPSIM), a biological specimens’ movement can be observed with resolution down to 50 nm and low photobleaching effect.

10:50 am Refreshments

11:00 am Seminar

Building 8, Room 241