A universal tunable nanofluidic diode via photoresponsive host-guest interactions

Inspired by biological ion channels, scientists have fabricated various artificial nanosystems. However, nanofluidic diode systems with replaceable functional groups are rarely reported. In this work, we demonstrated a universal tunable nanofluidic diode based on a conical polyimide nanochannel. Using host-guest interactions between beta-cyclodextrin and azobenzene, bidirectional nanofluidic diodes were prepared, and the degree of rectification could be adjusted with high precision by tuning the pH conditions. This work provides a novel approach to create a nanofluidic platform with replaceable surface functional groups, which has great potential in fields such as photosensitive nanofluidic devices, drug transport and release, and nanofluidic logic devices.