Preparation of graphene nano sheet bonded PDA/MOF microcapsules with immobilized glucose oxidase as a mimetic multi enzyme system for electrochemical sensing of glucose.
A novel amperometric biosensor for glucose detection was fabricated based on a mimetic multi enzyme system by combing mimetic enzymes (metal organic frameworks, MOFs) and glucose oxidase (GOx) The microcapsule constructed with polydopamine (PDA) and ZIF 8 using CaCO3 templates could be utilized not only to provide the biocompatible and non toxic microenvironment to immobilize GOx, but also as an efficient mimetic enzyme because of the peroxidase like properties of ZIF 8. The graphene nano sheets (rGO) were bonded to the PDA/ZIF 8 microcapsules to accelerate the electron transfer between the microcapsule and the electrode, and the resulted PDA/ZIF 8@rGO showed excellent electro catalytic activity towards H2O2. The mimetic multi enzyme system was fabricated when GOx was immobilized in the as prepared microcapsule, and the developed GOx/PDA/ZIF 8@rGO/GCE biosensor exhibited extraordinary electro detection performance for glucose with two wide linear ranges from 1 mM to 1.2 mM and 1.2 mM to 3.6 mM, and the limit of detection was 0.333 mM (S/N 3) Moreover, the good selectivity for glucose and satisfactory detection results in real samples of the prepared biosensor were also demonstrated.
Journal of materials chemistry. B