Using the ring-shaped protein TRAP to capture and confine gold nanodots on a surface.

The cavity of the toroidal protein TRAP (trp RNA-binding attenuation protein) is modified to capture gold nanodots in solution. By engineering a titanium-binding peptide onto one surface of the ring it is also possible to bind it specifically and tightly to a TiO2 surface. TRAP bound in this way is then used to capture gold nanodots and attach them to prepared surfaces.