• electrochemical sensor
• sweat
• uric acid
• tyrosine
• conductivity
• pH

The present work describes the development of an electrochemical platform measuring the concentrations of multiple analytes in sweat during physical activity. For this purpose, an indoaniline derivative (4-((4-aminophenyl)imino)- 2,6-dimethoxycyclohexa-2,5-dien-1-one) was designed and synthetized to serve as a voltammetric pH redox probe. The pH sensor built using this redox probe as sensitive layer showed a linear behavior in the pH range 2-12. Furthermore, it was tested in several biological matrices (blood, urine, and saliva) and beverages (tea, milk, and juice) showing a maximum deviation from the reference value of 0.2 pH units. Finally, the knowledge gained throughout this work was combined with laser scribed electrodes, a new kind of graphene-based electrodes in the field of sensing materials, allowed the II simultaneous monitoring of multiple analyte (pH, conductivity, uric acid, and tyrosine) in sweat through square wave voltammetry and electrochemical impedance spectroscopy. Calibration curves for each analyte were linear in the range of interest. Furthermore, a sweat sampler was designed and integrated into the device in order to standardize the sweat sampling during the sport session.