Highly deformable and conductive Ti3C2Tx MXene films for dopamine detection via synergistic particle intercalation and interface coupling

Rapid dopamine (DA) detection is vital for neurological diagnostics. In this work, a highly flexible and conductive freestanding film was obtained by vacuum-filtering a mixed ink containing Ti 3 C 2 T x MXene and CeO 2 nanoparticles (NPs). The film is constructed by introducing CeO 2 nanoparticles into Ti 3 C 2 T x interlayers, where interfacial Coulombic repulsion promotes the separation of adjacent Ti 3 C 2 T x layers, resulting in an open, crumpled 3D network. This architecture enlarges ion-transport channels, exposes more interfacial active sites, and maintains continuous conductive pathways for efficient charge transfer. Owing to the combined advantages of the conductive MXene skeleton and redox-active CeO 2 nanoparticles, the resulting flexible sensor exhibits excellent dopamine sensing performance, including a low detection limit of 0.0187 μM and two linear ranges of 0.05–1 μM and 1–160 μM. In addition, the composite film shows favorable flexibility, selectivity, reproducibility, and stability, suggesting its potential application in flexible wearable electrochemical sensing.