Original source: Materials Today
A team from Carnegie Mellon University, with collaboration from the University of Pittsburgh School of Medicine, have developed an advanced nanomaterial-based biosensing platform that can detect Covid-19 antibodies within just seconds. As a new tool in the fight against the virus, the innovation could be hugely significant, while the platform can also help quantify patient’s immunological response to new vaccines with a high degree of accuracy.
As reported in Advanced Materials [Ali et al. Adv. Mater. (2020) DOI: 10.1002/adma.202006647], the new platform identifies the presence of two of the virus’ antibodies, spike S1 protein and receptor binding domain (RBD), in only 5 microliters of blood. Antibody concentrations can be very low and still detected below one picomolar, equal to 0.15 nanograms per milliliter. This detection was achievable due to an electrochemical reaction within a handheld microfluidic device that transmits results almost immediately to a simple interface on a smartphone. Aerosol jet 3D printing was used to ensure the efficiency and accuracy of the testing platform.
Gold micropillar electrodes were printed at the nanoscale using aerosol droplets thermally sintered together, producing a rough and irregular surface that offers increased surface area of the micropillars and enhanced electrochemical reaction, where antibodies can attach themselves to antigens coated on the electrode. This geometry allows the micropillars to load more proteins for detection and, as the binding reaction between antibody and antigen is very selective, the test has a low error rate.
The researchers believe the inexpensive platform for home diagnostics could manage the spread of the virus, and also be manufactured quickly and scaled up for the production. As team leader Rahul Panat said “We utilized the latest advances in materials and manufacturing such as nanoparticle 3D printing to create a device that rapidly detects Covid-19 antibodies”. The platform allows detection in 10–12 seconds, the fastest yet reported.
The team had previously explored the potential of 3D biosensors for detecting neurotransmitters such as dopamine but realized their platform could offer a diagnostic capability that improved upon other sensing geometries. As the platform is generic, applying 3D printing to producing pathogenic biosensors enabled the quick detection of biomarkers for other infectious agents, including the ebola and zika viruses and HIV. Integration with wearable readouts could also help accessibility in remote areas, while 3D printing allows on-site and on-demand fabrication in the field, which could enhance the take-up of the technology. The next step for the team is large-scale human trials and to seek FDA approval.