Imprinting Chemical and Responsive Micropatterns into Metal–Organic Frameworks

Stamp of approval: Wet stamping allows metal–organic framework (MOF) crystals to be imprinted with micropatterns of various organic chemicals. Printing the MOFs with photochromic molecules and pH indicators generates stimuli-responsive micropatterns which change their appearance upon contact with specific chemicals (see picture), thus reporting the environmental "status" of the crystal.