Recently published research in the journal Nano Letters demonstrates the potential for quantum-based sensors to detect RNA viruses, such as SARS-CoV-2 (COVID-19), highlighting enhanced testing capabilities over more commonplace diagnostics, and providing a promising path to wide spread development and use.
In their paper, SARS-CoV-2 Quantum Sensor Based on Nitrogen-Vacancy Centers in Diamond, co-authors Changhao Li (MIT), Rouhollah Soleyman (Univeristy of Waterloo), Mohammad Kohandel (University of Waterloo), and Paola Cappellaro (MIT) propose a quantum sensor design based on leveraging properties of a nano-scale defect found in diamond lattices. The defect, called a nitrogen vacancy center, functions as a fluorescence marker sensitive to changes in its quantum spin magnetic environment, as may be influenced by biological processes, such as by viral RNA stimuli.
The proposed quantum sensor includes a coating, magnetically coupled to a nanodiamond and treated to bond with a biological stimuli, such as with COVID-19. The presence of the biological stimuli thus decouples the coating from the nanodiamond, disrupting the quantum spin of the nitrogen vacancy center, causing changes in its fluorescence as which may be observed with an optical sensor. Effectively, the presence of the viral stimuli functions as magnetic noise, disrupting the quantum properties of the nitrogen vacancy center, thereby inducing observable changes in photoluminescence indicative of the presence and volume of the viral stimuli.
Though the approach remains theoretical, the proposed diagnostic method offers potential improvements in sensitivity, testing time, and accuracy relative to other diagnostic techniques such as polymerase chain reaction (PCR) based diagnostics.
For example, the proposed methods can theoretically detect as few as a hundred viral RNA copies in a one second measurement and achieve false negative results at a rate of less than 1%, offering significant improvements over PCR based diagnostics.
With the researchers now turning their attention to developing a prototype, it’s worth noting that scaling the proposed quantum sensor for wide spread use appears promising. Mature synthetic diamond manufacturing methods can reportedly produce a single nanodiamond with a nitrogen vacancy center at negligible costs. Aspects of the chemical synthesis process required to enable the diagnostic method are also purportedly low cost, as the method requires only short sequences of c-DNA and RNA. Furthermore, the proposed diagnostic method is scalable to simultaneously measure multiple samples.
Beneficially, the proposed quantum sensor can be tailored for detecting other RNA viruses such as HIV and MERS. Thus, as with other technology verticals, medical diagnostics may experience significant disruption, advancement, and commercial opportunity on the back of advances in quantum technology.
