Tag Archives: Ting-Ting Wu

Looking at nanoparticles with your smartphone

Researcher Aydogan Ozcan and his team at the University of California at Los Angeles (UCLA) have developed a device which when attached to a smartphone allows the user to view viruses, bacteria, and/or nanoparticles. (Yikes, I understood nanoparticles were perceptible with haptic devices and that any work on developing optical capabilities was pretty rudimentary). From the UCLA Sept. 16, 2013 news release on EurekAlert,

Aydogan Ozcan, a professor of electrical engineering and bioengineering at the UCLA Henry Samueli School of Engineering and Applied Science, and his team have created a portable smartphone attachment that can be used to perform sophisticated field testing to detect viruses and bacteria without the need for bulky and expensive microscopes and lab equipment. The device weighs less than half a pound.

“This cellphone-based imaging platform could be used for specific and sensitive detection of sub-wavelength objects, including bacteria and viruses and therefore could enable the practice of nanotechnology and biomedical testing in field settings and even in remote and resource-limited environments,” Ozcan said. “These results also constitute the first time that single nanoparticles and viruses have been detected using a cellphone-based, field-portable imaging system.”

In the ACS [American Chemical Society]  Nano paper, Ozcan details a fluorescent microscope device fabricated by a 3-D printer that contains a color filter, an external lens and a laser diode. The diode illuminates fluid or solid samples at a steep angle of roughly 75 degrees. This oblique illumination avoids detection of scattered light that would otherwise interfere with the intended fluorescent image.

Using this device, which attaches directly to the camera module on a smartphone, Ozcan’s team was able to detect single human cytomegalovirus (HCMV) particles. HCMV is a common virus that can cause birth defects such as deafness and brain damage and can hasten the death of adults who have received organ implants, who are infected with the HIV virus or whose immune systems otherwise have been weakened. A single HCMV particle measures about 150–300 nanometers; a human hair is roughly 100,000 nanometers thick.

In a separate experiment, Ozcan’s team also detected nanoparticles — specially marked fluorescent beads made of polystyrene — as small as 90-100 nanometers.

To verify these results, researchers in Ozcan’s lab used other imaging devices, including a scanning electron microscope and a photon-counting confocal microscope. These experiments confirmed the findings made using the new cellphone-based imaging device.

For some reason I’m completely gobsmacked by the notion that I could look at nanoparticles on a smartphone at sometime in the foreseeable future.

Here’s a citation and a link to the paper,

Fluorescent Imaging of Single Nanoparticles and Viruses on a Smart Phone by Qingshan Wei, Hangfei Qi, Wei Luo, Derek Tseng , So Jung Ki, Zhe Wan, Zoltán Göröcs, Laurent A. Bentolila, Ting-Ting Wu, Ren Sun, and Aydogan Ozcan. ACS Nano, Article ASAP DOI: 10.1021/nn4037706 Publication Date (Web): September 9, 2013
Copyright © 2013 American Chemical Society

This paper is behind a paywall. Ozcan’s work was last mentioned here in a Jan. 21, 2013 posting about self-assembling liquid lenses.