Screen printing and laser-induced flexible sensors for the simultaneous sensitive detection of uric acid, tyrosine, and ascorbic acid in sweat.

A wearable sweat sensor, which could continuously monitor biomolecules related to the human physiological state, is emerging as a promising piece of health surveillance equipment. However, current sensors cannot simultaneously achieve a detection performance that equates to that of traditional sensors and satisfactory mechanical strength. Herein, a wearable sweat sensor with excellent detection performance and mechanical stability is designed and fabricated. Based on the integration of laser-induced graphene electrodes and a screen printing technique, this wearable sweat sensor could realize both the separate and simultaneous detection of uric acid (UA), tyrosine (Tyr), and ascorbic acid (AA) with high sensitivity. Good UA sensing performance in artificial sweat could be maintained even after 20 000 bends. In addition, the sensor can operate well in the wearing state or in a complex bovine whole blood sample. For the detection of human sweat, the changes in UA concentration after a purine-rich meal are continuously monitored and the results are in accordance with the corresponding serum UA detection results tested with a commercial serum UA meter. These results suggest its application potential in health monitoring for both gout patients and healthy humans.