Alexander Dallinger3,Federico Vivaldi1,2,Noemi Poma1,Andrea Bonini1,Denise Biagini1,Pietro Salvo2,Arianna Tavanti1,Francesco Greco3,4,Fabio Di Francesco1
University of Pisa1,National Research Council2,Graz University of Technology3,Scuola Superiore Sant’Anna4
Alexander Dallinger3,Federico Vivaldi1,2,Noemi Poma1,Andrea Bonini1,Denise Biagini1,Pietro Salvo2,Arianna Tavanti1,Francesco Greco3,4,Fabio Di Francesco1
University of Pisa1,National Research Council2,Graz University of Technology3,Scuola Superiore Sant’Anna4
Laser-Induced Graphene (LIG) created by laser scribing onto a polymer precursor like polyimide exhibits many interesting properties. Not only is it possible to create conductive patterns with a conductivity of around 25 S/cm, furthermore a high surface area A > 100 m<sup>2</sup>/g makes LIG suitable for applications in electrochemical (bio)sensing. By functionalization of the LIG electrodes with an indoaniline derivative (IAd) we measured pH and the concentration of uric acid and tyrosine on the same electrode by square wave voltammetry. Different LIG types were investigated and their electrochemical behaviour was characterized. A wearable device for sweat analysis was fabricated consisting of multilayer LIG electrodes and tracks of a LIG/Ag composite for enhanced conductivity, fabricated by a novel self-patterning method. The biosensor consisted of electrodes embedded into a medical-grade polyurethane together with a laser-cut sweat sampler, which ensured a constant sweat sampling. The calibration curves for tyrosine, uric acid and pH showed a linear behavior within the concentration levels of sweat. Finally, the performance of the biosensor was further evaluated in a real case scenario by analysing sweat over 30 minutes of sport activity.