High-strength, high-toughness regenerated cellulose/graphene oxide nanofluidic membrane with highly oriented and charged nanochannels for wearable sweat-monitoring systems

[Display omitted] •A bottom-up strategy is used to fabricate regenerated cellulose/GO nanofluidic membrane (TACM).•TACM had well-aligned nanochannels and negatively charged surfaces.•TACM exhibited good mechanical properties and excellent ionic conductivity (0.65 S m−1).•TACM was used in health monitoring and alerting systems. Nanofluids with directional, selective, and efficient ion-transport properties are widely used in energy-conversion research. However, designing wearable nanofluidic systems for personal health monitoring is challenging owing to the large size of the test equipment, complex preparation process, and stringent biosafety requirements. Herein, we present a bottom-up strategy, integrating structural orientation, densification, and charge, to prepare a robust regenerated cellulose/graphene oxide nanofluidic membrane (TACM) comprising well-aligned nanochannels (3–4 nm) and negatively charged surfaces. The TACM exhibited high strength (76.27 MPa) and toughness (24.56 MJ m−3) as well as excellent ionic conductivity (0.65 S m−1) at low salt concentrations (