Researchers over at UCLA Henry Samueli School of Engineering and Applied Science have created a smartphone attachment that can be used to detect viruses, bacteria and other nanoparticles thereby alleviating the need of carrying bulky and expensive microscope and lab equipment on field trips.

Aydogan Ozcan, a professor of electrical engineering and bioengineering at the UCLA, created the smartphone attachment along with his team and has described it in a paper titled “Fluorescent Imaging of Single Nanoparticles and Viruses on a Smart Phone” available here.

Ozcan claims that this smartphone based imaging platform can be used to detect “sub-wavelength objects, including bacteria and viruses” enabling students and researchers alike to carry out “nanotechnology and biomedical testing in field settings and even in remote and resource-limited environments.”

Ozcan’s attachment, which attaches to a smartphone’s camera, comprises of a 3D printer fabricated fluorescent microscope containing a colour filter, external lens and a laser diode. The sample – fluid or solid – is illuminated at a steep angle of about 75 degrees using the laser diode. The primary reason behind use of oblique illumination is to avoid detection of scattered light that would otherwise interfere with the intended fluorescent image.

Using this method, Ozcan and his team was able to detect single human cytomegalovirus (HCMV) particles, which measure just 150–300 nanometers and are known to cause birth defects such as deafness and brain damage. The team didn’t stop there as in a separate experiment it was able to detect nanoparticles as small as 90–100 nanometers.

The results achieved through the smartphone attachment were verified using other imaging devices including scanning electron microscope and a photon-counting confocal microscope.