Biosensor

Nanotechnology

Saliva

Analyte

Chemistry

Materials science

Chromatography

Biochemistry

Nature Biotechnology

Peripheral biochemical monitoring involves the use of wearable devices for minimally invasive or noninvasive measurement of analytes in biofluids such as interstitial fluid, saliva, tears and sweat. The goal in most cases is to obtain measurements that serve as surrogates for circulating analyte concentrations in blood. Key technological developments to date include continuous glucose monitors, which use an indwelling sensor needle to measure glucose in interstitial fluid, and device-integrated sweat stimulation for continuous access to analytes in sweat. Further development of continuous sensing technologies through new electrochemical sensing modalities will be a major focus of future research. While there has been much investment in wearable technologies to sense analytes, less effort has been directed to understanding the physiology of biofluid secretion. Elucidating the underlying biology is crucial for accelerating technological progress, as the biofluid itself often presents the greatest challenge in terms of sample volumes, secretion rates, filtration, active analyte channels, variable pH and salinity, analyte breakdown and other confounding factors. Heikenfeld et al. survey the range of biochemical analytes that can be sensed in dermal interstitial fluid, saliva and sweat, and outline criteria for tailoring sensor design to address the right analyte in the right body site for the right disease or wellness application.

Accessing analytes in biofluids for peripheral biochemical monitoring