A stamp-sized chip has been developed by scientists that will simplify Covid-19 testing and will deliver results on a smartphone in under an hour. The microfluidic chip used will measure the concentration of SARS-CoV-2 nucleocapsid (N) protein in the blood serum taken from a standard finger prick. The chip has been developed by researchers from Rice University. The research has been published in the journal ACS Sensors, and says that the nanobeads bind to SARS-CoV-2 N protein in the chip. After this, they transport it to an electrochemical sensor that can detect small amounts of the biomarker.
According to the researchers, the process introduced is simpler for sample handling when compared to swab-based PCR tests that are being widely used to check for COVID-19 infection. Peter Lillehoj, mechanical engineer, Rice lab highlighted that their device does not need a laboratory for testing as in case of RT-PCR. His statement noted that the entire test as well as generation of results can be done at the collection site, health clinic or even a pharmacy. The system is also easy to use and transportable.
The research was done using the existing biosensing tools in order to develop simple diagnostics similar to how a microneedle patch was introduced last year to diagnose malaria. The newly developed tool relies on a slightly more complex detection system but researchers say it can deliver accurate and quantitative results in a short time. The device was tested with donated blood serums from among healthy people along with the ones having COVID-19 infection.
While testing, 55 minutes turned out to be an optimum amount of time needed by the microchip to sense SARS-CoV-2 N protein (given the concentrations is as low as 50 picograms (billionths of a gram) per millilitre in the whole serum).
The blood sample is delivered to the chip with a capillary tube. The beads present there bind to capture antibodies and “generate a current proportional to the concentration of biomarker in the sample.” The potentiostat present will read the current and send a signal to its phone app.
