Colloquium: Euan McLeod

    Thursday, September 10, 2015 - 3:30pm - 5:00pm
    Meinel 307

    "Soft Nano-Photonic Systems: Nanolenses for On-Chip Holographic Imaging of Nanoparticles and Viruses"


    The fabrication of nanophotonic elements out of soft materials provides new frontiers for the integration of photonics with biosystems, and provides ways to realize microscopic devices that could not be made otherwise. Here we present one example: a nanoparticle and virus imaging platform enabled by nano-scale lenses that are self-assembled out of polyethylene glycol. Currently, nanoparticle sizing and imaging are typically performed using sophisticated laboratory-based electron microscopes or optical systems, even though such analyses can be time-intensive, costly, and/or not readily available in areas such as developing or rural regions. Rapid and inexpensive nanoparticle imaging and sizing is important in medical, environmental, and basic research, and could enable, for example, point-of-care quantification of viral load in HIV patients, multiplexed biochemical assays, or widespread air quality and water quality environmental monitoring. Here we perform accurate nanoparticle imaging and sizing using the combination of nanolenses and on-chip, in-line holography. This combined approach simultaneously provides high resolution, large field of view, and a cost-effective and field-portable hardware system. We can size particles of diameter 40 nm – 100 um, where the accuracy is +/- 11 nm for the 40 nm – 500 nm range. Our approach can size more than 10^5 particles simultaneously, can detect particles of various shapes, and can recover multi-modal distributions of sizes, all within a compact and inexpensive prototype device.

    Speaker Bio(s): 

    Euan McLeod is a new assistant professor at the College of Optical Sciences in the University of Arizona. He was previously a postdoc in Electrical Engineering and Bioengineering at UCLA, as well as a postdoc in Applied Physics at Caltech. He received his Ph.D. from Princeton University in 2009, and his B.S. from Caltech in 2004. Euan’s background and interests lie at the intersection of optics, nanoscience, and soft bio-materials science. He has published more than 20 papers on these topics in peer-reviewed journals. His most recent work has been a mixture of experiments and simulation with the goal of improving the sensitivity of lens-free holographic microscopy for imaging virus-sized and smaller particles.