In light of the properties of our HD-US-UiO-66-X, we decided to explore their use in heterogeneous catalysis. The challenging hydrolysis of peptide bond in glycylglycine (GG) was selected as the model reaction to investigate the significance of downsizing/defect formation of MOF nanoparticles on the overall catalytic performance (Figure ). HD-US-UiO-66-NH2 nanoMOF was subsequently selected for catalysis due to the potential H-bonding that could occur between the peptide substrate and the -NH2 group on the ligand, of -NH2 between H2O and substrate for the hydrolysis to occur, which could contribute to the overall catalysis.