Scientists at ETH Zurich and the University Hospital Zurich have now developed a method for the highly convenient, real-time monitoring of lipolysis by testing a person's exhalations during exercise.
The scientists have developed a sensor that uses a chip coated with a porous film of special semiconducting nanoparticles. The particles are tungsten trioxide that the researchers have implanted with single atoms of silicon.
The sensor measures a volatile lipid metabolite called acetone which is present in the air exhaled by a person. When fat burns, the body produces by-products such as acetone that finds its way into the blood.
The sensor can detect a single acetone molecule in hundred million molecules. It also measures acetone exclusively, so that more than 800 other known volatile components in exhalations do not affect the measurement.
The scientists are now planning to continue developing their measurement method so that they can eventually market it. They already have a prototype of the instrument.
The scientists are also working on developing gas sensors for other medically relevant molecules in exhalations, including ammonia to test kidney function, isoprene to test cholesterol metabolism and various aldehydes for the early detection of lung cancer.