Potential Uses for Smartphone-Based Diagnostic Tool Described

By LabMedica International staff writers
Posted on 31 Oct 2017

Two recent papers described potential applications for a smartphone-based instrument that can evaluate biological samples with the accuracy of clinical laboratory analyzers but at a fraction of the cost.

Investigators at the University of Illinois College of Engineering (Urbana-Champaign, USA) utilized a smartphone's internal rear-facing camera as a high-resolution spectrometer for measuring the colorimetric absorption spectrum, fluorescence emission spectrum, and resonant reflection spectrum from a microfluidic cartridge inserted into the measurement light path. Under user selection, the instrument gathered light from either the white “flash” LED of the smartphone or an integrated green laser diode to direct illumination into a liquid test sample or onto a photonic crystal biosensor.

Image: The system uses a commercial smartphone to acquire and interpret real-time images of an enzymatic amplification reaction that takes place in a silicon microfluidic chip that generates green fluorescence and displays a visual read-out of the test. The system is composed of an unmodified smartphone and a portable 3-dimensional-printed cradle that supports the optical and electrical components, and interfaces with the rear-facing camera of the smartphone (Photo courtesy of the Micro & Nanotechnology Laboratory, University of Illinois at Urbana-Champaign).

Light emerging from each type of assay was gathered via optical fiber and passed through a diffraction grating placed directly over the smartphone camera to generate spectra from the assay when an image was collected. Each sensing modality was associated with a unique configuration of a microfluidic “stick” containing a linear array of liquid chambers that were swiped through the instrument while the smartphone captured video, and the software automatically selected spectra representative of each compartment.

Potential uses for the smartphone analyzer were described in a paper in the August 18, 2017, online edition of the journal Analytical Chemistry, where the investigators used the device to detect four horse respiratory diseases, and in a second paper in the August 22, 2017, online edition of the journal Biomedical Microdevices, where the device was used in a point-of-care setting to detect and quantify the presence of Zika, Dengue, and Chikungunya virus in a droplet of whole blood.

Contributing author Fu Sun, a research assistant at the University of Illinois College of Engineering, said, "I entered graduate school with the hope to make a better world by developing biomedical devices that can facilitate effective disease prevention, diagnosis, or treatment. This project is in line with my goal since it provides a point-of-care solution for the fast diagnosis of infectious diseases. Connected to a cloud database through a smartphone, it helps healthcare providers in the field embrace the era of big data and the Internet of Things."

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University of Illinois College of Engineering