Some sports clothing already contains embedded nanoparticles that hinder growth of stinky bacteria that feed on sweat. Now, there’s a new smart textile that can analyze sweat and potentially help its wearer figure out whether dehydration is imminent (J. Mater. Chem., DOI: 10.1039/c2jm34898e). Researchers led by Nicola Coppedè of the Institute of Materials for Electronics & Magnetism, in Parma, Italy, functionalized cotton fibers with a conductive polymer composed of poly(3,4-ethylenedioxythiophene) and poly(styrene sulfonate) and then integrated a silver wire into the textile to complete the circuit. When someone wearing the fabric perspires, redox reactions between salt ions in sweat and the silver wire result in ion flow through the material. These ion currents could be used to indicate changes in the salt concentrations in sweat that occur during dehydration. As the salt concentration in sweat rises, so does the likelihood that the athlete is becoming dehydrated, Coppedè says. This is the first electronic fabric capable of detecting salt concentrations in aqueous, sweaty conditions, he notes. The team suggests the functionalized textile could also be used for diagnosing or monitoring people with cystic fibrosis, because their sweat contains abnormal concentrations of salt ions.