Pd nanoparticles decorated ultrathin 2D metal–organic framework nanosheets with enhanced peroxidase–mimic activity and colorimetric assay of glucose

In addition to size, shape and morphology, enzyme–mimetic property could be efficiently regulated by controlling composition, forming complexes or hybrids, and surface modification. Herein, Pd nanoparticles with an average diameter of 2.52 nm were decorated on ultrathin 2D copper(II)-porphyrin derived metal–organic framework (MOF) nanosheets by a simple reduction method for catalytic activity regulation. In comparison with other nanozymes, the as-synthesized Pd modified 2D MOF hybrid nanosheets (Pd@Cu-TCPP(Fe)) presented excellent peroxidase–mimic activity, exhibiting an even superior catalytic ability towards H2O2 with a Michaelis–Menten constant as low as 2.33 mM. Based on a cascade reaction between glucose oxidase and Pd@Cu-TCPP(Fe), a colorimetric method for the detection of glucose was established and validated with a wide linear range (0.2–8.0 mM), good recovery (89.5–94.2%) and nice reproducibility (3.65%). All these features guaranteed its excellent ability for glucose determination in human cerebrospinal fluids. This study could offer a valuable reference for constructing novel optical biosensors.