Smartphone attachment detects viruses and bacteria

Aydogan Ozcan, a professor of electrical engineering and bioengineering at the UCLA Henry Samueli School of Engineering and Applied Science led a team that developed the lightweight device.

‘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 in a statement. ‘These results also constitute the first time that single nanoparticles and viruses have been detected using a cellphone-based, field-portable imaging system.’

The research is published in the American Chemical Society’s journal ACS Nano.

Capturing clear images of objects such as a single virus or a nanoparticle is difficult because the optical signal strength and contrast are very low for objects that are smaller than the wavelength of light.

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