Entrapment of protein in nanotubes formed by a nanochannel and ion-channel hybrid structure of anodic alumina.

The nanochannel (in a porous layer) and ion-channel (in a barrier layer) hybrid structure of anodic alumina is used as a protein-trapping device. The transmembrane potential drives the electromigration of the charged proteins (FITC-labeled) into the nanochannels, but electromigration across the barrier layer is impossible due to the size-exclusion effect. As a result, the proteins can be continuously trapped in the nanochannels.