A bioinspired double-confining strategy enables highly practical target gas detection via promoted solvated ion transport

Electronic signal transmission-based gas sensing materials have been facing the technical bottlenecks of high operating temperature, high power consumption, and adverse humidity interference. In contrast, ionic signal transmission-based human olfaction efficiently functions in complex environmental conditions, which inspires the proposal of a unique gas sensing strategy. Herein, a bionic olfactory film is designed through confining ionic liquids (ILs) (i.e., [Bmim][Tf₂N]) within both graphene oxide (GO) nanochannels and sub-nanometer volumes of a polymer matrix. As validated by both experimental data and molecular dynamics (MD) simulations, efficient triethylamine (TEA) detection is achieved due to the double confinement effect which significantly enhances the solvated cation (TEA-[Bmim]⁺) transport. Under ambient conditions, the films with optimized compositions demonstrate an exceptional response to 20 ppm TEA (1013.52 ± 14.31%), rapid response and recovery times (7.6 s and 26.1 s, respectively), and a low limit of detection (200 ppb). Combined with high selectivity, stability, anti-humidity interference, and low power consumption, the as-prepared bionic olfactory film with double-confined ion channels provides new insights to develop ionic signal transmission-based bionic integrated sensing systems for next-generation robots with intelligent perception toward external stimuli.