Above: A graphic that demonstrates how the smartphone virus scanner works. The virus-containing cavities are 4.5 micrometres across and 9 micrometres apart. Credit: © 2019 Minagawa et al.
Most of us are similar with ‘viruses’ and malware relating to our computers or smartphones, but Yoshihiro Minagawa, a researcher from the University of Tokyo has taken it on literally – he has invented a portable, low-cost, battery-powered device that pairs with a smartphone, which was tested with viruses but could also detect other biological markers. His initial findings, together with other teammates were published recently in the journal, Lab on a Chip.
The current leading method to assess the presence of viruses and other biological markers of disease is effective but large and expensive. It is prohibitively difficult for use in many situations, especially due to certain economic and geographic factors. Although highly accurate at counting viruses, these tools are just too cumbersome for many situations, especially when rapid diagnosis is required.
“I wanted to produce a useful tool for inaccessible or less-affluent communities that can help in the fight against diseases such as influenza,” said Minagawa. “Diagnosis is a critical factor of disease prevention. Our device paves the way for better access to essential diagnostic tools.”
WHAT’S IT ABOUT
The device is about the size of a brick with a slot on top in which you place a smartphone such that its camera looks through a small lens to the inside of the device. Through a custom-made smartphone app, individual viruses can be seen.
Viruses are held in place on a clear surface in tiny cavities lit with an LED. The surface and fluid surrounding it were designed so that only when a cavity has a virus inside does incident light — the light that directly hits the surface — from the LED redirect up to the camera, manifesting in a bright pixel in an otherwise dark void. Each cavity is 48 femtolitres (quadrillionths of a litre) — it would take over 10 million of these to hold a single human tear.
ON THE RECORD
“Given two equal samples containing influenza, our system detected about 60 percent of the number of viruses as the fluorescence microscope. But it's much faster at doing so and more than adequate to produce good estimates for accurate diagnoses,” Minagawa added in a statement. “What's really amazing is that our device is about 100 times more sensitive than a commercial rapid influenza test kit, and it's not just limited to that kind of virus.”
