A device to detect SARS-CoV-2 in saliva samples is one step closer to a real-world application. A unique technology, which was developed by researchers from the Institute of Physics of the Czech Academy of Sciences, has shown sensitivity comparable to that of PCR testing.
Its serial production and prototype development are now being prepared in collaboration with CARDAM R&D. The resulting device, which, plainly speaking, can be envisioned as a drink vending machine with a cup dispenser, might be a helpful solution when testing large amounts of people, with no need to deploy qualified personnel to operate the machine.
At the heart of the method, which delivers high precision results in detecting whether and how much of SARS-CoV-2 is present in human saliva, lies a quartz crystal biochip oscillating at a certain frequency.
“The material of the biochip has been developed specifically to capture viral particles. The surface of the biochip is coated with a thin layer of a special polymer that employs a unique method to capture target particles directly from the bio-sample. In doing so, it ignores everything else in the sample,” Hana Lísalová said, the head of the team from the Institute of Physics of the Czech Academy of Sciences (FZU), which developed the chip. This polymer was designed by the researchers in the group, who have already filed a patent application to seek legal protection of the polymer’s specific composition.
According to proof-of-concept results, the sensitivity of the biochip to saliva samples is equal to that of the PCR samples of nasopharyngeal swabs. In addition to detecting the presence of the virus, the test measures the concentration of the virus within around 15 minutes.
“In a blinded study involving real clinical samples taken with nasopharyngeal swabs and processed with the PCR testing method, we have observed a 100% compliance with our testing results. Theoretically, the sensitivity of the biosensor might be high enough also in the case of testing saliva samples but we are still waiting to see the results of an extensive future study of oral rinse samples.
Coffee vending machine
The physicists are now working together with CARDAM developers to propose and built up a robotic system able to analyse large numbers of samples. In very simple terms, it can be described as a coffee vending machine with a cup dispenser, which works in a reverse sequence. “A person would come up to the machine, collect a cup containing a special solution, rinse his/her mouth, and return the cup to the machine. The machine would then collect the liquid, transfer it to the biochip to perform the analysis, and finally would give either a green signal - everything is all right, or a red one - caution, high risk of a positive result. If the latter was the case, a recommendation to take a standardized test would follow,” Alexandr Dejneka, who cooperates with Hana Lísalová on the project, said, explaining the research concept.
The automated biosensor might protect citizens or employees, primarily in manufacturing, iron, and steel industries as well as at schools, hospitals, etc. Importantly, the system would not require any qualified operators to perform the collection, instead a technician to supervise the system would suffice.
The technology, validated last summer at the laboratories of the Biological Centre of the Czech Academy of Sciences and the Faculty of Natural Sciences of the South-Bohemian University in České Budějovice, with the support of the MATCA National Competence Centre, funded by the Technology Agency of the Czech Republic, is now preparing to perform pilot testing of the prototype and to fine-tune individual features of the system.
The CARDAM R&D centre is a joint venture of the Institute of Physics of the Czech Academy of Sciences, Česká zbrojovka Group, and Beneš a Lát.
In addition to the robotic system, the physicists have developed a portable multi-channel biosensor to be used directly in the field. The device, designed as a portable case, will be used for food safety inspections by the Czech Police Protection Service in late 2021.
“Its purpose is to check the safety of food consumed by protected persons, including, among others, key government and state officials. Unlike standard testing, our biochip technology can significantly reduce detection time, the results are available almost instantly and directly on the spot,” Hana Lísalová added.
Alexandr Dejneka, Ph.D.,
The Head of the Department of Optical and Biophysical Systems of the FZU
+ 420 266 052 141