Developing new tools to tackle the COVID-19 pandemic is becoming increasingly critical as a fifth wave washes over the global landscape. With infections on the rise, a novel, extremely precise and speedy biosensing method has been identified by MIT researchers who have demonstrated that it would be possible to develop a sensor, based on quantum physics, that could detect the SARS-CoV-2 virus.
Though the work is still theoretical, the new novel approach is detailed in a paper published in the journal Nano Letters, describing a series of mathematical simulations based on quantum effects. What’s more, is that the researchers also believe the method could be adapted and reconfigured to detect almost any existing or emerging virus.
Quantum Sensor Approach
The innovative quantum sensor approach proposes a molecular transducer designed for nitrogen vacancy (NV) centers in nanodiamonds. To put it another way, the method utilizes atomic-scale defects in the nanodiamonds to translate the presence of SARS-CoV-2 RNA into an unambiguous noise signal that can be optically readout.
What this involves is using a material that can be applied as a magnetically coupled coating to the nanodiamonds containing the NV centers. This coating would be treated to only react and bond with the specific RNA sequence of the virus.
When the material comes into contact with the RNA sequence, they form a bond that disrupts the magnetic connection and results in a variance in the fluorescence of the nanodiamond, which can be readily detected with a laser-based optical sensor.
While the use of diamonds sounds like a costly endeavor for rapid testing on the required scale, the sensors, in fact, only use low-cost materials, and as the diamonds are of nanosize, the biosensing devices could be upscaled to analyze entire batches of samples simultaneously, according to the researchers.
The RNA-tuned gadolinium-based coating with its organic molecules can be fabricated using standard chemical processes and materials, and the lasers needed to read the results are similar to commercially available cheap green laser pointers.
Furthermore, the team says that the proposed method is not only fast but promises to reach a sensitivity down to a few hundred RNA copies with a false-negative rate of less than 1%.
The hybrid sensor that the MIT-based team proposes can also be further implemented with a variety of solid-state defects and substrates, which can identify and diagnose alternative RNA viruses and be incorporated into emerging CRISPR technology.
Faster, Better Virus Diagnostics
This approach is promising because it could, in effect, supplant the current rapid tests and those that detect viral proteins via polymerase chain reaction (PCR) tests that take many hours to process individually. Furthermore, current tests are not able to identify the amount of virus present and may generate false-positive rates in excess of 25%, making the proposed devices faster, better virus diagnostic tools.
While the work in the study was based on a series of mathematical simulations, they did prove that the approach can work in theory, so the next step is taking the theory and building a working device in the laboratory to confirm the working principle.
We don’t know how long it will take to do the final demonstration.
Changhao Li, MIT Doctoral Student and Co-Author of the Study
The team plans to do a basic proof-of-principle lab test and then work on ways to improve the system to optimize it for use in real-world virus diagnosis applications. The challenge in building the devices is assembling a multidisciplinary team with expertise in quantum physics, engineering, chemistry and biology to build and assemble working devices complete with working molecules that bind with virus RNA.
According to the researchers, the fundamental principle of the method can be adapted to any virus, including any new viruses that may emerge, by simply modifying the compounds that are attached to the nanodiamond sensors to match the standard material of a particular target virus.
The devices would hold a strong advantage over the current gold-standard PCR tests due to the fact that the devices would still be able to produce results in minutes rather than hours.
References and Further Reading
MIT News | Massachusetts Institute of Technology. (2021) Sensor based on quantum physics could detect SARS-CoV-2 virus. [online] Available at: https://news.mit.edu/2021/quantum-sensor-detect-covid-1220