| Enzyme has become an ideal catalyst for many chemical reactions due to its high efficiency,greenness,and high selectivity.However,the poor stability of enzymes and the difficulty in recycling limit their applications in industry.Enzyme immobilization technology is an effective method to overcome this difficulty,in which the choice of immobilized carrier is crucial.Metal organic frameworks(MOFs)are ideal carriers for enzyme-immobilization because of their adjustable structure,pore size,and performance.In this work,glucose oxidase(GOx)and a zirconium-based biomimetic MOFs MOF-545(Fe)are combined to achieve the immobilization of GOx,a simulated multi-enzyme system is established to realize a one-step catalytic cascade reaction for glucose detection.GOx was immobilized on MOF-545(Fe)to construct a simulated multi-enzyme system GOx@MOF-545(Fe),and the successful load of GOx was proved by FTIR,EDS,CLSM and other characterization methods.MOF-545(Fe)not only served as a support for the enzyme immobilization,but also contributed its catalytic activity to co-operate with GOx for the cascade reactions.Based on GOx@MOF-545(Fe),a colorimetric biosensor for glucose rapid detection was achieved with a low limit of detection(0.28 ?M)and high specificity.Meanwhile,due to the protection of MOF-545(Fe),the immobilized enzyme exhibited excellent reusability and stability,e.g.long-term stability,thermal stability and anti-organic solvent stability.After being stored at room temperature for 7 days,the immobilized enzyme retained 92% of activity,while only 40% of activity of free enzyme was retained.And the immobilized enzyme maintained 71% of its initial activity after 5 cycles.This strategy of combining MOF mimics and natural enzymes for tandem catalysis may provide a novel and facile approach to design a highly efficient,stable,functional chemoenzyme composites catalyst,which holds great promise for applications in biosensing,biopharmaceutical and industrial catalysis. |
PDF Full Text Request