Researchers at MIT have designed a quantum sensor to detect SARS-CoV-2. While the device is still theoretical, the researchers have used mathematical simulations to show its potential, and the data and design indicate that it may be faster, more accurate, and less expensive than the current gold-standard technique, PCR. The system is based on nanodiamonds to which viral RNA binds, causing a change in the magnetic properties of the system and leading to a measurable change in fluorescence.
It looks as if COVID-19 is here to stay, and unless the virus mutates to become significantly less harmful or we develop new treatments that largely negate its harmful effects in everyone, COVID-19 testing is also here to stay. Rapid lateral flow tests have been useful in providing a quick answer on infection status, but they are not very accurate.
PCR is the current gold standard testing technique, but it is inconvenient, time consuming, and costly. It also does not provide a quantitative measurement about the amount of virus present in a sample, and can potentially suffer from false negative rates of over 25%.
There is clear room for improvement here, so these researchers set out to design a sensor that addresses many of these issues, using mathematical modeling to test whether their design had potential. Their proposed technology consists of nanodiamonds containing small defects called nitrogen vacancy centers. An entire nanodiamond array is covered with a gadolinium-based coating that contains specific binding sites for viral RNA.
When the viral RNA binds to the coating, it should disrupt the magnetic properties of the material, leading to a change in the fluorescent properties of the diamonds, which the researchers should be able to measure using a commonly available laser-based optical sensor. The researchers theorize that the new sensor will produce a false negative rate of less than 1%, demonstrating a significant advance on existing testing techniques.
The technique should also be fast, taking just a few minutes, and the sensor can be made using low-cost materials. Another advantage includes the potential to scale the technology so that it can assess many samples at the same time. While the work is currently purely theoretical, the researchers aim to make a prototype as soon as possible.
Once made, even if the technology isn’t quite as accurate as they hope, the potential for such a huge leap in accuracy is tantalizing.
Study in Nano Letters: SARS-CoV-2 Quantum Sensor Based on Nitrogen-Vacancy Centers in Diamond