Polyamidoamine dendrimer as a spacer for the immobilization of glucose oxidase in capillary enzyme microreactor

Polyamidoamine dendrimer (PAMAM) is one of a number of dendritic polymers with precise molecular structure, highly geometric symmetry, and a large number of terminal groups. In this study, different generations of PAMAM (G0–G4) were introduced onto the inner wall of fused-silica capillaries by microwave irradiation and a new type of glucose oxidase (GOx) capillary enzyme microreactor was developed based on enzyme immobilization in the prepared PAMAM-grafted fused-silica capillaries. The optimal enzymolysis conditions for β-d-glucose in the microreactor were evaluated by capillary zone electrophoresis. In addition, the enzymolysis efficiencies of different generations of PAMAM–GOx capillary enzyme microreactor were compared. The results indicate that enzymolysis efficiency increased with increasing generations of PAMAM. The experimental results provide the possibility for the development and application of an online immobilized capillary enzyme microreactor.