A method for coating colloidal particles with molecularly imprinted silica films

A method of coating colloidal particles with molecularly imprinted silica films of nano size is described. The imprinted film is prepared via a sacrificial spacer'' imprinting technique with testosterone as the template and silver colloidal particles as the core, and then characterized by transmission electron microscopy and infrared spectroscopy. Steady-state binding results show that the imprinted film has a highly selective recognition ability for template molecules. Moreover, due to its thickness in nanometres, the imprinted film presents a very fast kinetic profile for binding templates, with a saturation time less than 10 min. Furthermore, this technique offers a unique means of fine-tuning the thickness of imprinted materials on a core.