Anyone who has traveled during the times of COVID-19 will know the trial of having to get tested within a specific pre-flight timeframe. Those unfortunate enough to have been sick will know the stress of wanting quick results in a convenient fashion.
In a bid to make COVID-19 tests cheaper and more accessible, organic chemist Vittorio Saggiomo, from the Bionanotechnology group at Wageningen University & Research in the Netherlands, turned to common household appliances — specifically the coffee machine capsule. Saggiomo and his team's study on the subject is published in preprint server ChemArxiv.
Identifying the ideal COVID-19 test for home use
Different COVID-19 tests have different benefits and disadvantages for certain situations. The PCR test, for example, is the most accurate. However, this test requires a carefully regulated temperature cycle using special equipment in a lab, and therefore takes longer and is more expensive than other test types.
The Lateral Flow Test (LFT) is much cheaper and faster, though it is also less accurate and only detects the disease in people with high viral loads.
Saggiomo and his team's test kits, dubbed CoroNaspresso are a type of loop-mediated isothermal amplification (Lamp) COVID-19 test kit made using a simmering pan and a Nespresso coffee capsule.
Finally is out, our super cheap, easy to produce in millions, almost universal, and with low waste impact nucleic acid detection (LAMP test for #COVID19) non-instrumental device. The answer is: a Nespresso capsule. The question is: why we did this? 1/nhttps://t.co/ZHe9JHqUcy pic.twitter.com/Llkb3VNhl4— Vittorio Saggiomo (@V_Saggiomo) March 23, 2021
A great advantage of the Lamp test, as Mark Lorch, Professor of Science Communication and Chemistry at the University of Hull in the United Kingdom wrote in an article for The Conversation, is that it can be carried out at a fixed temperature (approximately 65°C, or 150°F).
This, as well as the fact that the test uses a simple acid-based color indicator to indicate positive or negative, made it ideal for Saggiomo to try to replicate at home using simple home appliances.
Coffee capsules for COVID-19 home testing
In order to regulate temperature for tests, scientists typically use electric thermostats. However, as Saggiomo was working from home and was trying to find a cheap, easy solution, he turned to substances called phase change materials that absorb heat as they melt — meaning they maintain a constant temperature.
Saggiomo found a wax made of a phase change material that melted at the exact temperature he needed. He then constructed a device to house the Lamp reaction tubes and chunks of wax.
All of this needed to be inserted into a casing that could be heated without melting. The perfect candidate, it turns out, was a staple of Saggiomo's breakfast routine: the Nespresso coffee machine capsule.
After testing several methods for heating the device, Saggiomo found the best method to be a simple pan of simmering water on a stovetop.
Promising COVID-19 test kit test results
Saggiomo asked his team members to test the resulting "CoroNaspresso" device in their own homes. In these tests, swabs from six people correctly identified three cases of COVID-19 by showing different colors.
The team of researchers says the test, including the capsules, phase changing wax, and vials would be easy to produce in millions. People could swab for genetic material at home and then heat the capsules to get their results.
The devices are also cheap at €0.20 ($0.24) and are easy to use, and largely recyclable. Sagiommo and his team's work with the CoroNaspresso test kits is a brilliant example of using materials at home in order to carry out a function typically reserved for advanced machines.