The smartphone is known for advanced mobile capabilities with combined functions including personal digital assistance, portable media players, digital cameras, and a fully integrated global positioning system, enhancing end-user experience.
Advancements in smartphones are continuing to progress with an effort to making these phones capable of being applied in sophisticated fields of application including laboratory analysis.
A team of scientists from the bioengineering department at California NanoSystems Institute (CNSI) and the University of California, Los Angeles (UCLA) have tested the performance of a smartphone installed with a portable fluorescence microscopy platform to help identify nanoparticles and viruses.
The handheld device has a fluorescent imaging module (a 450nm laser diode) with an incidence angle of approximately 75°, a thin-film interference filter to cancel out background noise, and an external lens that can provide a magnification of the specimen.
Being able to capture images of single nanoparticles is becoming an important practice for scientists in the field of biomedicine. Light microscopy techniques such as photothermal imaging and dark-field scattering microscopy have made it possible to visualize single nanoparticles in support of diagnostics.
However, with advancements in light microscopy technology, the use of such imaging techniques is expensive to use and so the effort is to help miniaturize sophisticated and expensive microscopy systems and bulky optical equipment into a platform that is easy to use, flexible and can be taken further afield into remote locations to perform single-virus detection.
An advance in smartphone-based imaging could help physicians in far-flung and resource-limited locations monitor how well treatments for infections are working. Credit: American Chemical Society.
The improved cell phone attachment has a laser beam, a cover glass, an external lens, and a long-pass filter. The cell phone also contains a lens and a CMOS sensor.
The screen to this cell phone has a field-portable fluorescent imager that uses a laser-diode-based excitation capability with a resolution at 450nm allowing the device to illuminate the sample plane. The LP filter helps block the scattered excitation beam, which helps isolate the individual nanoparticles and viruses. Aydogan Ozcan and colleagues used this measurement technique to test for particles labeled with human cytomegaloviruses, a virus that is a part of the Herpes family of viruses.
Both structural components work together to help determine virus particles and viral load, which can then provide information on the severity of an infection to help tailor treatment for the infection.
This portable device is a lightweight imaging technique that will become a key component in field-based fluorescent microscopy in resource-limited regions of the world.