A group of UCL researchers along with the i-sense Mckendry group explained that the quantum sensing ability of the nanodiamonds can be used to sense the paper-based diagnostic tests. This would even allow detecting diseases like HIV and COVID-19 earlier.
What are paper-based diagnostic tests?
If you know about the pregnancy test via paper then you would be familiar with it. Similarly in this test, a fluid sample is placed in a strip, and the color change marks the positive result with the detection of virus proteins or DNA. Viruses like HIV or SARS-CoV-2 can be detected with it. The result can be easily obtained without any diagnosis as the test doesn’t need to be performed in any lab.
The biggest advantage of this test is that it can detect the disease at an early stage which seems to be very beneficial for us. It will help to stop the spread of the diseases and a potential treatment can be carried on the infected ones from the earlier stage.
Professor Rachel McKendry, the lead author of the study said “Our proof-of-concept study shows how quantum technologies can be used to detect ultralow levels of virus in a patient sample, enabling much earlier diagnosis. We have focused on the detection of HIV, but our approach is very flexible and can be easily adapted to other diseases and biomarker types. We are working on adapting our approach to COVID-19. We believe that this transformative new technology will benefit patients and protect populations from infectious diseases.”
In the current situation, the researchers are working on accommodating the new technology to detect the COVID-19 easily, and in the next part, a developed handheld device would be introduced so that the test can take place anywhere anytime. The current process is been carried on with microscope in the laboratory.
How does the process work?
In the regular structure of a diamond, the quantum properties have a defect which creates the nitrogen-vacancy (NV) centre. The NV centre can signal the presence of antigen or other molecules with the emission of bright fluorescent light. But in the nanodiamonds, the quantum properties allow the emission to change selectively by which the signal can set at a fixed frequency with the help of a microwave field and it can be separated from the background fluorescence accurately. The optical result displayed a much better advancement in sensitivity as compared to gold nanoparticles.
After that, a ten-minute constant-temperature amplification step was included where a photocopy of the RNA was multiplied and then the researchers could catch the HIV RNA at a single-molecule level in a sample.
Dr Ben Miller the first author of the study said “Paper-based lateral flow tests with gold nanoparticles do not require laboratory analysis, making them particularly useful in low resource settings and where access to healthcare is limited. They are low cost, portable, and user friendly. However, these tests currently lack the sensitivity to detect very low levels of biomarkers. By replacing commonly used gold nanoparticles with fluorescent nanodiamonds in this new design, and selectively modulating their (already bright) emission of light, we have been able to separate their signal from the unwanted background fluorescence of the test strip, dramatically improving sensitivity.”
Adding to it co-author of the study Professor John Morton said, “This interdisciplinary collaboration between UCLQ and the i-sense team in the LCN is a fantastic illustration of how foundational work on quantum systems, such as NV centre in diamond, can evolve from the lab and play a crucial role in real-world applications in sensing and diagnostics. Researchers at UCLQ are exploring and enabling the impact of these and other quantum technologies by working with industry and other academic research groups.”
We expect the researcher to bring this technology soon into our smartphone and other handy devices. It will help people all around the world to take precautions and start their treatment at an early stage of any disease which will help to recover easily.
Source – ucl