New Interface for Purification of Proteins: One-Dimensional TiO₂ Nanotubes Decorated by Fe₃O₄ Nanoparticles

In this work, a high surface area interface, based on anodic one-dimensional (1D) TiO 2 nanotubes homogeneously decorated by Fe 3 O 4 nanoparticles (TiO 2 NTs@Fe 3 O 4 NPs) is reported for the first time for an unprecedented purification of His-tagged recombinant proteins. Excellent purification results were achieved from the model protein mixture, as well as from the whole cell lysate (with His-tagged ubiquitin). Compared to a conventional immobilized-metal affinity chromatography (IMAC) system, specific isolation of selected His-tagged proteins on behalf of other proteins was significantly enhanced on TiO 2 NTs@Fe 3 O 4 NPs interface under optimized binding and elution conditions. The combination of specific isolation properties, magnetic features, biocompatibility, and ease of preparation of this material consisting of two basic metal oxides makes it a suitable candidate for future purification of recombinant proteins in biotechnology. The principally new material bears a large potential to open new pathways for discoveries in nanobiotechnology and nanomedicine.