Smartphone-Powered POCKET Offers Point-of-Care DNA Testing at Low Cost and in a Compact Size
Using a smartphone for analysis — and as a heater, thanks to a custom CPU-hungry software package — brings the size down
Researchers from Cornell University, the University of Science and Technology of China, and a series of research hospitals and medical universities have unveiled a pocket-sized, smartphone-powered point-of-care testing kit for DNA analysis: POCKET.
"Point-of-care testing (POCT) has broad applications in resource-limited settings," the researchers explain in the paper's abstract, brought to our attention by Phys.org. "Here, a POCT platform termed POCKET (point-of-care kit for the entire test) is demonstrated that is ultraportable and versatile for analyzing multiple types of DNA in different fields in a sample-to-answer manner.
"The POCKET is less than 100g and smaller than 25cm in length. The kit consists of an integrated chip (i-chip) and a foldable box (f-box). The i-chip integrates the sample preparation with a previously unidentified, triple signal amplification. The f-box uses a smartphone as a heater, a signal detector, and a result readout."
A key feature of the POCKET is its use of the smartphone not just for data processing and visualization but as a key part of the device itself: the heater. "We controlled the chip heating by a heat-up application with functions of reading the internal temperature sensor and heating up the smartphone," the team explains. "The temperature was controlled by both the number and the time of the running algorithms. After the temperature reached 37°C, the i-chip was placed on the back of the smartphone for incubation. To avoid the heat loss and save the energy, the smartphone with the i-chip was placed in a thermos package with a temperature display bar."
The system proved its performance during testing, too: "We detected different types of DNA from clinics to environment to food to agriculture," the researchers claim. "The detection is sensitive (<103 copies/ml), specific (single-base differentiation), speedy (<2 hours), and stable (>10 weeks shelf life). This inexpensive, ultraportable POCKET platform may become a versatile sample-to-answer platform for clinical diagnostics, food safety, agricultural protection, and environmental monitoring."
The team's work has been published in the journal Science Advances under open-access terms.