Strain-promoted "click" chemistry is used to post-synthetically modify the pore walls of azide-functionalized mesoporous bio-MOF-100 (N(3)-bio-MOF-100). The reactions proceed in high yield and produce no byproduct. This new method was used to introduce various functional groups into the MOF mesopores, including succinimidyl ester bioconjugation moieties that allow for straightforward coupling of biomolecules to the pore walls.