Wearable Biosensors Measure The Levels Of Vitamin C In Sweat

Research suggests that vitamin C can help to support recovery from certain aspects of infection which includes COVID-19, and if the vitamin is shown to be useful in this context these sensors could have a place in the response to the current pandemic. 

“Wearable sensors have traditionally been focused on their use in tracking physical activity, or for monitoring disease pathologies, like in diabetes,” said Juliane Sempionatto, a researcher involved in the study. “This is the first demonstration of using an enzyme-based approach to track changes in the level of a necessary vitamin, and opens a new frontier in the wearable device arena.”

This wearable innovation consists of an adhesive flexible patch that users can non-invasively attach to their skin, by stimulating sweat in the underlying skin the sensors can generate enough sweat to be used for the vitamin C level analysis. The device structure is flexible and contains ascorbate oxidase enzymes that convert vitamin C into dehydroascorbic acid, consuming oxygen in the process which generates an electrical current that the electrodes within the devices can sense to wirelessly provide a data readout that is proportional to the level of vitamin C present in the sweat. 

This biosensor technology has been tested on human volunteers, finding that the sensors could sensitively track the levels of vitamin C over a period of a couple hours; the sensors even detected changes in vitamin C levels when the volunteers drank fruit juice or took supplements; findings have been published in ACS Sensors. 

Vitamin C plays important roles in proper nutrition and in maintaining a healthy immune system, as well as having potential as a therapeutic in its own right: Its antioxidant properties may even have potential in treating heart disease and certain cancers. Additionally, high doses of vitamin C have been linked to decreased mortality rates in sepsis as well as in acute respiratory distress syndrome, both of which can be present in those with COVID-19. 

If this new non-invasive technology is shown to be useful in the context of COVID-19 these sensors may help clinicians to monitor and optimize patient levels of vitamin C depending on the individual’s needs. In more mainstream and routine use these devices have potential to help people to make dietary and nutritional changes. 

“Ultimately, this sort of device would be valuable for supporting behavioral changes around diet and nutrition,” said Sempionatto. “A user could track not just vitamin C, but other nutrients - a multivitamin patch, if you will. This is a field that will keep growing fast.” The UC San Diego team is closely collaborating with a major global nutrition company DSM towards the use of wearable sensors for personal nutrition.

“Despite the rapid development of wearable biosensors, the potential of these devices to guide personalized nutrition has not yet been reported,” said Joseph Wang, another researcher involved in the study. “I hope that the new epidermal patch will facilitate the use of wearable sensors for non-invasive nutrition status assessments and tracking of nutrient uptake toward detecting and correcting nutritional deficiencies, assessing adherence to vitamin intake, and supporting dietary behavior change.”