Accurate rapid tests made from smart graphene paper
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Loading... - Eugene Martinez
- 28 Mar 2023
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A team led by ETH Zurich chemical engineers Chih-Jen Shih and Andrew deMello have developed a rapid test system made of smart graphene paper. It only costs a few Swiss Rappen per test strip, is easy to use but is as accurate as lab measurements. The approach will impact more than just disease monitoring.
Rapid pregnancy and COVID-19 tests have a great advantage over other medical analyses: they are so simple that anyone can perform the test themselves, virtually anywhere. This is due to the robust principle behind these microfluidic methods, whereby aqueous solutions diffuse through a paper test strip with the aid of capillary forces. During this process, antibodies capture the target substances, such as virus particles or pregnancy hormones, and concentrate them at a desired location. A staining system then slowly makes the increasingly concentrated target substance visible as a stripe.
As simple and reliable as this basic principle is, visual assessment of the results can be difficult. The question of whether we really can see a line or whether we’re just imagining it has probably been on all of our minds at least once since the outbreak of the COVID-19 pandemic.
This is exactly where the invention of the ETH team comes in. They have found a way to form conductive electrodes directly inside the test strip paper. As the target substance is captured, it triggers an electronic signal. This makes measurements much faster, more sensitive and more accurate.
Making low-cost paper technology better
Shih and deMello share a passion: "Our biggest incentive is to improve basic chemical and biological experiments in ways that create new scientific opportunities." This is exactly what their research groups have now succeeded in doing with the rapid tests. A host of analytical applications benefit from the researchers’ combining simple and cost-effective paper-based microfluidics with the sensitivity and accuracy of electronic measurement techniques. From patients being able to monitor blood biomarkers themselves, to soil, air and water sampling in the field, to disease testing in remote parts of the world in a matter of minutes - the potential range of applications covers virtually all chemical, biological and medical analyses that can be performed in aqueous solutions. Read More…
