Simultaneous detection of tyrosine and uric acid in sweat using CoWO4@CNT with a hydrogel modified electrochemical biosensor

Abstract

The levels of uric acid (UA) and tyrosine (Tyr) in sweat reflect a person's overall health. However, simultaneously identifying several components in sweat remains challenging. Here, we achieve simultaneous detection of UA and Tyr by synthesizing CoWO₄@CNT in a single step using a hydrothermal method. CoWO₄'s high catalytic efficacy and large CNT reaction area allow the detection of 1–1000 μM UA (LOD = 0.14 μM) and 5–1000 μM Tyr (LOD = 4.2 μM). To increase sweat collection, we developed a polydopamine–polyacrylamide (PDA–PAM) hydrogel with a sweat absorption rate of up to 226%. Finally, by monitoring sweat at various times of day, our sensors can discriminate between UA and Tyr in real sweat, and the results are consistent with the individuals' activity levels. Overall, the effective electrocatalytically active materials and PDA–PAM hydrogel improve the detection of UA and Tyr. The remarkable performance of CoWO₄@CNT in real samples shows that it has the potential to improve health detection and real-time sweat analysis.