Multimedia Gallery
New sensor detects tiny individual nanoparticles
Pictured here are arrays of self-referenced and self-heterodyned Whispering-Gallery Raman microlasers for single nanoparticle detection. A "pump" laser generates a single Raman lasing mode inside the silica resonators. Upon the landing of a nanoparticle on the resonator, a Raman laser circulating inside the resonator undergoes mode splitting, leading to two new lasing modes in different colors. Monitoring the changes in the color difference (frequency difference) enables detection and measuring of nanoparticles with single particle resolution.
The new sensor--developed by a team of researchers at Washington University in St. Louis (WUSTL), led by Lan Yang, the Das Family Career Development Associate Professor in Electrical and Systems Engineering, and collaborators at Tsinghua University in China--can detect and count nanoparticles--engineered materials about a billionth of a meter in size--at sizes as small as 10 nanometers, one at a time. The researchers say the sensor could potentially detect much smaller particles, viruses and small molecules. Funding for the research was provided by the National Science Foundation (NSF) and the U.S. Army Research Office.
Yangs microsensor is in a class called "whispering gallery" mode resonators because it works similarly to the renowned whispering gallery in Londons St. Pauls Cathedral, where a person on one side of the dome can hear a message spoken to the wall by another person on the other side. Yangs device does much the same thing with light frequencies rather than audible ones.
[This research is associated with the project "Enhanced Raman and Rayleigh scattering in an ultrahigh-Q micro resonator for detection, identification and measurement of nanoparticles," supported by NSF grant CBET 12-64750.]
To read more about this research, see the WUSTL news story Engineers develop new sensor to detect tiny individual nanoparticles. (Date of Image: 2013)
Credit: Image by J. Zhu, B. Peng, S.K. Ozdemir, L. Yang, Electrical and Systems Engineering Department, Washington University in St. Louis
Images and other media in the National Science Foundation Multimedia Gallery are available for use in print and electronic material by NSF employees, members of the media, university staff, teachers and the general public. All media in the gallery are intended for personal, educational and nonprofit/non-commercial use only.
Images credited to the National Science Foundation, a federal agency, are in the public domain. The images were created by employees of the United States Government as part of their official duties or prepared by contractors as "works for hire" for NSF. You may freely use NSF-credited images and, at your discretion, credit NSF with a "Courtesy: National Science Foundation" notation.
Additional information about general usage can be found in Conditions.
Also Available:
Download the high-resolution JPG version of the image. (3.8 MB)
Use your mouse to right-click (Mac users may need to Ctrl-click) the link above and choose the option that will save the file or target to your computer.