A fouling-resistant, affinity-based platform enables cheap, simultaneous sensing of multiple biomarkers
Handheld electrochemical sensors have revolutionized at-home medical testing for diabetics, but they have not yet been successfully applied to diagnosing other conditions. These sensors are based on the activity of an enzyme, and there are only a limited number of enzymes that can be used to detect biomarkers of human disease. An alternative, much more broadly applicable sensing strategy based on molecular binding events, such as antibodies directed against specific biomarkers, has been investigated, but these sensors fall victim to the rapid accumulation of “fouling” substances on their conductive surfaces, which deactivate them. Existing antifouling coatings are difficult to mass-manufacture, suffer from quality and consistency issues, and are not very effective.
eRapid is a low-cost, affinity-based electrochemical sensing platform that can simultaneously detect a broad range of biomarkers with high sensitivity and selectivity in complex biological fluids, using as little as a single drop of blood. It features a novel, antifouling nanocomposite coating to which probes are attached that are specific to the target biomarker. When the target binds to the probe, it attracts a second probe to create a “sandwich” that triggers the formation of a local precipitate on the coated electrode surface that is electrically active. The size of the electrical signal generated correlates with the concentration of the target detected in the sample, and because the precipitate forms locally, many different biomarkers can be tested in parallel on the same sample.
The eRapid system has been shown to successfully detect IL6, insulin, and glucagon, among other clinically relevant target molecules ranging in size from 100 Da to 150,000 Da. The sensors can also be washed and reused multiple times with minimal signal loss, allowing repeated monitoring of biomarkers easily and at low cost.
eRapid has potential applications in the following settings:
- Home healthcare
- Longitudinal biomarker monitoring
- Environmental monitoring
This technology is currently being de-risked at the Wyss Institute.