Simultaneous Cu doping and growth of TiO2 nanocrystalline array film as a glucose biosensor

Doping additional ions into a semiconductor is a potential strategy to modify the electronic structure of semiconductor materials. By using highly reactive colloidal Cu clusters as doping precursor, we present here the successful doping of Cu ions into a TiO2 nanocrystalline material that simultaneously transformed from amorphous anodic TiO2 nanotubes through a dissolution and recrystallization process. The Cu-doped TiO2 nanoparticle (Cu-TNP) film was characterized by X-ray diffraction, scanning and transmission electron microscopy and Raman spectroscopy. The Cu-TNPs show a rugby-like shape with exposed active {101} and {001} facets and the long-axis parallel to the [001] lattice direction. The substitutional Cu2+ ion dopants in the TiO2 nanocrystals caused the swelling of the crystalline unit cell. Such an efficient doping design facilitates the improvement of nanostructured TiO2 as a potential biosensor for glucose molecules.