A new rapid coronavirus test developed by KAUST scientists can deliver highly precise results in less than 15 minutes.
Diagnosis, which combines electrochemical biosensors with engineered protein constructs, enables clinicians to identify parts of the virus quickly and precisely, something that was previously only possible with slower genetic engineering. The entire facility can work on unprocessed blood or saliva samples at the time of patient care. There is no need for laborious sample preparation or a central diagnostic laboratory.
“The combination of state-of-the-art bioelectronic hardware, materials science technology and synthetic biology protein design really makes it possible to simplify and accelerate coronavirus tests,” says Raik Grünberg, biochemist at KAUST, who co-led the study.
Grünberg and his KAUST colleagues, including Sahika Inal and Stefan Arold, are now working with retail partners to adapt their prototype on a laboratory scale. They hope to develop a portable tabletop device that can be used to contain the COVID-19 pandemic.
“This biosensor technology could be adapted to detect other pathogens and, as such, will have a major impact on fighting pandemics – now and in the future,” says Inal.
Coronavirus testing is still important. Despite rising vaccination rates in Saudi Arabia and around the world, global COVID-19 cases remain worryingly high and public health officials need methods to quickly identify people infected with the disease in order to avoid virus transmission to limit.
Current test paradigms can generally be divided into two camps: either they detect viral RNA by genetic means, which can be slow and involve the enzymatic amplification of trace molecular signals, or they capture viral proteins (called antigens) in some way that’s quick, but not nearly as accurate.
The new KAUST technology now combines the speed of protein detection with the precision of genetic tests. “Even if a sample contains only a single virus particle, our platform will recognize this,” says Keying Guo, postdoc in Inal’s laboratory and co-author of the study with his KAUST colleagues Shofarul Wustoni and Anil Koklu.
The system starts with a virus-specific nanobody, a type of binding protein that can be engineered to adhere to fragments of various coronaviruses, including those responsible for COVID-19 and Middle East Respiratory Syndrome (MERS). The nanobody is bound by a series of biochemical linkers to a thin layer of gold that, when an electric current is added, controls the flow of current through the semiconductor film to which it is connected. The presence of nanobody-bound viral proteins alters this flow, creating a signal that is amplified to measurable levels by a device known as an organic electrochemical transistor.
The researchers first refined their test on human saliva and blood samples that were spiked with pieces of protein from the coronaviruses that cause MERS and COVID-19. They then worked with doctors from KAUST Health in Thuwal and scientists from the King Faisal Specialist Hospital and Research Center in Riyadh to validate the assay on clinical samples, both saliva and nasal swabs, taken from patients.
The speed, versatility and performance compared to standard genetic tests underscore the potential of the new method to supplement or possibly replace existing diagnoses for COVID-19 and future pandemics.