The strong interactions between microperoxidase (MP-11) and Tb-mesoMOF were identified via Raman spectroscopic studies, which revealed that MP-11 molecules interact with the framework of Tb-mesoMOF through pi center dot center dot center dot pi interactions between the heme of MP-11 and the conjugated triazine and benzene rings in the organic ligand of Tb-mesoMOF. The strong interactions facilitate the retention of MP-11 molecules within the metal-organic framework (MOP) pores, which is in striking contrast with the severe leaching of MP-11 from MCM-41 due to the lack of specific interactions between enzyme molecules and the mesoporous silica material.