Scientists develop electronic skin patches that analyze sweat to measure wearer’s vitamin C levels

Vitamin C can support the immune system, play a key role in wound healing, and may even help with the recovery of COVID-19. So, how do you know if you’re taking enough vitamin C? Well, a wearable sweat analysis sensor will tell you soon.

Scientists develop electronic skin patches that analyze sweat to measure wearer's vitamin C levels

The prototype device, developed by scientists at the University of California, San Diego, uses a thin, elastic, stretchable patch that temporarily sticks to the user’s skin. It contains flexible electrodes, which in turn contain an enzyme called ascorbic acid oxidase. Once attached, the patch can make the skin sweat. If sweat contains any vitamin C, ascorbic acid oxidase converts it into dehydrogenated and ascorbic acid. This process not only consumes oxygen, but also generates current.

Scientists develop electronic skin patches that analyze sweat to measure wearer's vitamin C levels

Measured by sensors, the strength of this current varies with the level of vitamin C in sweat, which corresponds to the level of vitamin C in the blood. Once connected to a small circuit board, the current prototype can transmit this data wirelessly for further analysis.

Over a two-hour period, the sensor patch was able to accurately track changes in vitamin C levels in four subjects who had taken vitamin C supplements and fruit juices rich in vitamin C. It also effectively detects vitamins in tears and saliva, plus the technique is likely to be adapted to sense other compounds.

Scientists develop electronic skin patches that analyze sweat to measure wearer's vitamin C levels

“It’s not just vitamin C that a user can track — it’s a multivitamin patch, if you will, ” said Juliane Sempionatto, a doctoral student and lead author of the study. “This is an area that will continue to grow rapidly. “

Scientists develop electronic skin patches that analyze sweat to measure wearer's vitamin C levels

The research paper, chaired by Professor Joseph Wang, was recently published in the journal ACS Sensors.