When bodily fluids such as blood are tested for infectious diseases and unhealthy protein levels, they’re typically mixed with antibodies or other biological reactants to produce a positive or negative reaction. Researchers from Arizona State University (ASU) have now come up with an alternative testing system that they claim is just as accurate, but much simpler, quicker and cheaper. It utilizes LED lights and simple microelectronic amplifiers, and actually uses the sample itself as a diagnostic tool. Because it integrates the sample into the process, inventors Antonia Garcia and John Schneider call their device the Integrascope.
A drop of blood, saliva, urine or other fluid is placed on the Integrascope’s superhydrophobic viewing surface, which repels liquid and thus causes the drop to bead up. A spherical depression in the surface holds the drop in place. A drop of liquid containing nanoparticles or microparticles is then placed on top of the sample drop, the two mixing together into one big drop.
Due to surface tension, the drop acts as a lens for light which is shined through it from one side by a near-infrared LED. A light detector on the opposite side measures the intensity and scatter of the beam created by the drop/lens. As the drop evaporates, the particles will begin to stick together if the targeted agent is present. The agent itself will eventually migrate to the center of the drop, leaving the particles not yet stuck together to move to the surface. All this sticking together and migrating affects the way that the light passes through the drop, and this is measured by the detector to determine if specific antigens or excess proteins are present. The process delivers results in less than two minutes.
Not only can the Integrascope detect specific agents, the ASU researchers say, but it can also assess overall health by measuring total protein in human serum, saliva and urine.
Needless to say, a device such as this would be particularly well-received in developing nations. “To have a global impact, we need to have accurate and sensitive tools that can help health care providers treat patients at a low cost during their first visit”, said Garcia. “Our goal is to translate this technology and design into a rugged and easy-to-use device that we would give away for free to clinics. The only costs involved with using the Integrascope would be in the drop of particles and a small piece of a superhydrophobic surface – about US$1 to $2.”
The research was recently published in the journal Nature Precedings.
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