The continuous monitoring of human health can greatly benefit from devices that can be worn comfortably or seamlessly integrated in household objects, constituting “health-centered” domotics. One of the key aspects for these devices to be successful is to be invisibly integrated and disappear in the background of our lives. Our group works on thin film devices made with plastic materials that can be used for electrochemically sensing of common analytes from easily accessible bodily fluids (e.g. sweat, saliva, urine) and can be easily multiplexed. I will describe electrochemical transistors that detect ionic species either directly present in body fluids or resulting from a selective enzymatic reaction (e.g. ammonia from creatinine) at physiological levels. I will also show that non-charged molecules can be detected by making use of custom-processed polymer membranes that act as “synthetic enzymes”. Using these membranes in conjunction with electrochemical transistors we demonstrate that we are able to measure physiological levels of cortisol in real human sweat. Importantly, transistors can amplify signals and I will show what architectures must be used to observe 1000x amplification of sensing currents.
Finally we have developed a process that allows us to fabricate sensor arrays on flexible substrates thereby opening the door towards ultra-thin, flexible sensor arrays for wearable technologies.
