Paper introducing new optofluidic approach for detection of single viruses named Editor’s Pick by Optics Letters

Thursday, October 11, 2018
Erin Foley

A team of Baskin Engineering researchers, including Electrical and Computer Engineering Professor and Kapany Chair of Optoelectronics Holger Schmidt, graduate students Jennifer Black, Vahid Ganjalizadeh, and postdoctoral researcher Joshua Parks, published research findings on a new optofluidic approach to multimode interference (MMI) multiplexing that incorporates a stacked channel design to enable velocity and spectral multiplexing of single particles. The paper, Multi-channel velocity multiplexing of single virus detection on an optofluidic chip, was named Editor’s Pick by Optics Letters.

The paper describes a new way of MMI-based optofluidic multiplexing by intersecting a single multi-spot pattern with multiple fluidic channels. This “stacked channel” approach, implemented using a liquid-core MMI waveguide on an optofluidic chip made from polydimethylsiloxane (PDMS), a silicon-based organic polymer, allows for both velocity and spectral multiplexing of particles.

The stacked channel design was used for velocity multiplexing of two different influenza viruses using a single wavelength. Both H3N2 and H1N1 viruses were fluorescently tagged with the same color dye and pulled separately through two different channels at different speeds. Using a single excitation laser to create multi-spot signals, single H3N2 and H1N1 viruses were identified simultaneously based on their velocity.

“Exciting biological targets with multiple light spots is a key component of our approach to detecting single molecules on a chip,” said Schmidt. “The technique demonstrated in this paper adds another capability to our toolbox and will allow us to expand to analyzing many targets simultaneously.”