Functionalized cellulose nanocrystals construct self-healing nanocomposite hydrogel-based sweat sensors for glucose detection

Based on the structural characteristics of the abundant active sites on its surface, cellulose nanocrystals (CNCs) not only have widespread applications as ideal reinforcements in composites, but also they demonstrate significant potential for applications in electrochemical sensing. Herein, the glucose oxidase (GOx) was successfully loaded onto the surface of CNCs using bovine serum albumin (BSA) as a bridge, and the CNCs@BSA-GOx/PVA self-healing nanocomposite hydrogels were prepared together with poly(vinyl alcohol) (PVA). The maximum fracture stress of the hydrogel was 0.79 MPa, and the self-healing rate was as high as 87.85 % at room temperature, showing excellent mechanical properties and self-healing efficiency. In addition, a hydrogel-based sweat sensor for the electrochemical detection of sweat glucose were constructed by using a simple strategy. This glucose sweat sensor exhibited a low detection limit (8.2 μM) and good linearity (R2 = 0.9948). This work provides a novel approach for the development of sweat sensors, making it possible to achieve sensitive detection of glucose in sweat.