[MOS] NOVEMBER 18, 2014, Oliver Bruns, MIT

[Zina M Queen]

Seminar on
Modern Optics and Spectroscopy

Short-wavelength infra red (SWIR) quantum dots for high-speed imaging of physiology in freely moving mice

Oliver Bruns,
Massachusetts Institute of Technology
Tuesday, November 18, 2014
12:00 – 1:00 p.m.
In vivo optical imaging has the unique advantage of combining high-resolution with fast acquisition speeds. Fluorescent labels can be detected in this setting with very high sensitivity, ultimately allowing the detection and tracking of single labeled biological entities. Compared to other imaging modalities, this allows studying fast biological processes in great detail.  Imaging deep in tissue or a whole animal is limited by tissue autofluorescence, tissue and blood absorbance, and scattering. Imaging in the short-wavelength infrared (SWIR) (1000-2000nm) addresses these challenges simultaneously as there is minimal autofluorescence, significantly reduced light absorptions from blood and other structures and scattering is strongly diminished.  Here we introduce high quality SWIR emitting core shell quantum dots as versatile labels for this window. These dots exhibit a dramatically higher QY (up to 30%) compared to previous SWIR labels.  Applying this new technology for SWIR imaging allows us to perform biological imaging on a new level. Due to their tunable emission and small size we can perform color SWIR imaging of metabolic processes at video rate, demonstrating the impressive benefits of the SWIR band and the potential of designing experiments with multi colors similar to the visible. The emission signal is strong enough to detect and track single aggregate particles while combining high resolution with high penetration depth and high speed. We used this to generate detailed three dimensional quantitative flow maps of brain vasculature in only a few minutes while still resolving the smallest capillaries. We clearly image the drastic differences between healthy brain tissue and a tumor in the brain.  Applying our novel QD technology in the SWIR band allows us to bring optical imaging to a new level by imaging very fast physiological processes, for example enabling visualization of the heart rate in awake and freely moving mice. The combination of speed, penetration depth, and sensitivity of this new technology will enable studies which could only be done in smaller animals like fly or zebra fish larvae to be performed in mice, a mammalian model more relevant to humans.
Grier Room, MIT Bldg 34-401
Refreshments served after the lecture
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mailman.mit.edu/pipermail/mos/attachments/20141110/2ff8b8ca/attachment.htm