cid proline at the site where proline is present. This breakthrough in cost-effective protein splitting took place at Arizona State University in 2006.[21]Titanium dioxide on silica is being developed as a form of odor control in cat litter. The purchased photocatalyst is vastly cheaper than the purchased silica beads, per usage, and prolongs their effective odor-eliminating life substantially.Titanium dioxide is also used as a material in the memristor, a new electronic circuit element.It can be employed for solar energy conversion based on dye, polymer, or quantum dot sensitized nanocrystalline TiO2 solar cells using conjugated polymers as solid electrolytes[22] .It has also been recently incorporated as a photocatalyst into dental bleaching products. It allows the use of decreased concentrations of hydrogen peroxide in the bleaching agent, thus claimed to achieve similar bleaching effects with less side effects (e.g.:transient sensitivity, change in tooth surface topography, etc