Summary:

- This article discusses the development of a smart sticker that can continuously monitor vitamin C levels in the body.
- The sticker uses a biosensor that measures the concentration of vitamin C in the interstitial fluid, which is the fluid between cells, and provides real-time data on vitamin C levels.
- This technology could help people track their vitamin C intake and ensure they are getting the recommended amount, which is important for maintaining a healthy immune system and preventing deficiencies.