The disease is recognized and the immune status of the population is a key factor in the control of the epidemic. For this reason, the detection of antigens and antibodies is very important. The devices currently used for this purpose, known as point-of-view (POC) devices, are an option for rapid evaluation. However, their understanding still needs to be improved. Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) achieved this improvement by creating a nanobiosensor based on gold nanowires. Initially intended only for the detection of antigens and antibodies related to COVID-19, the biosensor is also transferred to other biomarkers, as the researchers report in the scientific journal ACS Publications (DOI: 10.1021/acssensors.2c01686).
It is now known through many studies that to detect SARS-CoV-2, the so-called POC lateral flow assays (LFT) is a very accurate method and reverse transcriptase-polymerase chain reaction, commonly called PCR test. Several advantages of LFT over PCR testing include rapid detection, on-site testing, low cost, and operation without laboratory equipment.
However, a major weakness of POC biosensors is that their sensitivity depends on bacterial load. At a high viral load, the sensitivity is one hundred percent, while at a low viral load, the sensitivity can drop below ten percent. This can lead to negative test results.
The goal of the HZDR researchers is to develop a sensor system that can also be used to detect low bacterial load and provide fast and accurate results. To do this, Dr. Larysa Baraban and her colleagues at the HZDR-Institute for Cancer Radiopharmaceutical Research use gold nanowires, which can be used to identify different biomolecules such as enzymes, proteins and antibodies. This method is combined with electrochemical impedance spectroscopy, a technique that provides information about various processes at the electrode-electrolyte interface, including charge transfer, diffusion transport, and electrical double formation, as well as on the characteristics of measurement systems. This includes the resistance of the solution and the weakness or porosity of the electrode surface.
Baraban says about the project, “In our work, we created a nanoscale biosensor chip that consists of six pairs of gold nanowire devices that are interconnected to detect SARS-CoV-2 antigens and antibodies.” “This makes it possible to detect whether antigens related to COVID-19 and the corresponding antibodies appear during and after infection. We think that the method is also transferred to other biomarkers and pathogens . The active layer must be modified to focus on the biomolecule for this purpose.
Ideas and discussions are currently going on in the industry so that the sensor can be produced on a large scale and cheaply.
