Novel Wearable Sensor Detects Metabolites with Molecule-Shaped Holes

Sep, 2022 - By WMR

Novel wearable sensor detects tiniest levels of several common nutrients as well as biological compounds in human sweat, which could be used for indicators of human health

With the advancement in technology, number of wearable sensors identifying metabolites in sweat continues to grow that; however, current technology has limitations in what it can detect and these sensors are not always reusable. Now a group of researchers at the California Institute of Technology (Caltech) have developed a new sensor, which uses molecularly imprinted polymer to detect smallest changes in levels of several biological compounds as well as nutrients in human sweat.

Among several options available in wearable sensors detecting metabolites in users sweat, the researchers explored a better-performing alternative. The team designed a sensor incorporating a film of polymer generating an electrical current whenever it is in contact with sweat. Moreover, it forms a layer between the skin and the film for a second polymer that is imprinted molecularly. In this imprinting process, the team embedded molecules of the specific metabolites in the polymer when it is in a liquid form. This allowed the polymer to set in a rubber-like form then with a chemical process, the team removed the molecules from it. The resulting polymer sheet contained small molded holes having exact shape and size of the molecules.

When user’s sweat comes into contact with polymer, the liquid starts flowing through these open holes when it is not containing any metabolites. This further creates an electrical current as it goes to other polymer present beneath. However, when the sweat contains higher levels of metabolite, the molecules plug several holes, which indicates that not much amount of sweat went through and the current produced is weaker. Hence, the concentration of the targeted metabolite can be measured in the users sweat by monitoring the electrical signals that the sensor generates. The team has tested the new technology on subjects in lab, and now it soon will be tested in bigger clinical trials.