Fabrication of Both TiO 2 Nanostructures and Cysteine-Modified AAO Membranes and Their Application in Chiral Selective Transport of Proteins

Chirality is a widespread phenomenon in nature, which plays an essential role in the metabolism of organisms. It is highly associated with a lot of significant biological processes, such as transport and translocation of proteins. Herein, we reported a chiral anodic aluminum oxide (AAO) nanochannel modified with both titanium dioxide (TiO 2 ) nanostructures and cysteine (Cys) enantiomers and explored the chirality response on bovine serum albumin (BSA) transport. The results showed that BSA was preferentially transported through the nanochannel modified with l -Cys due to chiral interaction, which indicated that chirality would influence the transport process of proteins strongly. TiO 2 nanostructures, which were anchored on the wall of a nanochannel, improved the sensitivity of the selective transport process of BSA. Moreover, we found that the effect of TiO 2 nanostructure modification was more stable and excellent when the pore diameter of AAO membrane was 40–70 nm. This study provided a platform for the research of chiral selective transport of proteins, and introduced metal oxide nanostructures into a biomimetic nanochannel as well.