Fabrication of metal-organic framework-containing silica-colloidal crystals for vapor sensing.

The excellent sorption kinetics, reversibility, and guest-induced changes in the MOF structure and/or properties make them intriguing candidates, in particular, for sensing. However, only a few of these changes (mainly luminescence quenching) have been explored for sensing purposes due to their small magnitude or the diffi culty in their measurement. Integrating MOFs into devices will allow the measurement of these changes due to the uptake of guest molecules. [ 6 ] For example, the effective refractive index of a MOF should be sensitive to volatile molecules due to pore fi lling. This can lead to MOF-based optical devices for sensing these guest molecules. Here, we report an approach based on MOF-enshrouded colloidal crystals. Elsewhere we have described MOF-based sensors that rely upon the refractive-index modulation of Fabry–Pérot interference peaks or localized surface plasmon extinction peaks. [ 7 ]