Bioengineers at the University of Illinois at Urbana-Champaign have turned a smartphone into a portable diagnostic laboratory capable of performing a range of spectrum analyses that is currently done using large and expensive stationary machines. The investigators built a smartphone attachment that utilizes the smartphone’s camera to analyze the colorimetric absorption spectrum, fluorescence emission spectrum, and resonant reflection spectrum of a sample placed inside a custom microfluidic cartridge.
The device is called transmission-reflectance-intensity (TRI)-Analyzer and the prototype cost only $550 to build, which is considerably less than commercial machines currently in use in hospitals around the world. Moreover, the price is expected to be much lower if it ends up being manufactured in large quantities.
Since the three spectrum analysis techniques are already in use and assays for them are readily available, the researchers believe that introducing this technology into clinical practice will be very easy. To demonstrate this, they ran two assays currently on the market using their TRI-Analyzer, including an ELISA assay that detects fetal fibronectin protein and a fluorescent assay that spots phenylalanine. The results correlated quite closely with the findings produced by expensive commercial equipment.
The device uses a green laser or the phone’s built-in LED flash to illuminate the sample, the light from which is redirected through an optical fiber into a diffraction grating and onward into the phone’s camera. An app then captures and analyzes the image, providing diagnostic results without much operator assistance. Because the sample cartridges can be placed inside a linear gun magazine-like device, multiple tests can be performed one after another in quick succession.