High-performance Peroxidase-like Nanomaterials For Applications In Biosensin

Enzymes are highly efficient biocatalysts,and they are widely used in the transformation of biomolecules in the fields of industry,medicine,and biology.Although they have good application prospects,they often have inherent disadvantages such as high preparation and purification costs,poor operational stability,sensitivity to the reaction environment,and difficulty in recycling.Taking environmental sensitivity as an example,in the environment of strong acid and alkali,the integrity and spatial structure of the primary structure of the enzyme molecule will be destroyed.Subsequent denaturation of the enzyme molecule results in a loss of catalytic activity.This result limits their further applications.To overcome these shortcomings,researchers have been working to explore artificial enzyme mimics.Nanozymes,as potential supplements or substitutes for natural enzymes,have broad application prospects in biosensing,bioimaging,antibacterial,antioxidant,therapeutic,environmental protection and other fields.On this basis,the first part of this paper synthesized a Prussian blue-gold fiber-based peroxidase for the detection of hydrogen peroxide（H₂O₂）and uric acid（UA）,which has higher reusability compared with natural enzymes,and easier to recycle,and because of its flexibility,it can be made into a wearable kit,expanding the application of nanozymes.The second part utilizes silicon dioxide（SiO₂）template to fabricate porous Fe-N-C single-atom nanozymes.Single-atom nanozymes have similar atomic positions to natural enzymes,so single-atom nanozymes are expected to have enzyme-like activities.Fe-N-C nanozymes with peroxidase-like activity can catalyze the generation of·OH from hydrogen peroxide at the active site of Fe Nx,which is similar to that of natural metalloproteases.On the basis of colorimetric analysis,we also developed an electrochemical sensor based on Fe-N-C nanoparticles for the detection of H₂O₂.Here,we report the use of stretchable styrene-ethylene-butylene-styrene（SEBS）fibers as a conductive susbtrate to simultaneously load Au nanowire and Prussian blue（PB）as biosensing interfaces.Accordingly,due to the synergistic catalytic effect between Au nanowire（Au NWs）and PB,the as-obtained flexible PB/Au fibers can not only show the potential as wearable biosensors but also serve as high-performance peroxidase-like nanozymes.The prepared fiber composites can be used for colorimetric sensing of H₂O₂ and UA,respectively,and can be reused for more than 20 times.The relative error（RD）is less than 10%in serum sample analysis,which can be used in actual detection.This work verifies the application potential of nanozymes in the field of flexible wearables and expands the application of nanozymes in the field of biosensingThe single-atom nanozyme Fe-N-C was synthesized by a strategy of utilizing SiO₂template.Compared with N-C without Fe atom,it has better peroxidase-like activity and H₂O₂ electrochemical sensing performance.Fe-N-C single-atom nanozymes have better adaptability to extreme p H and temperature.In H₂O₂ colorimetric detection,the lowest detection limit can reach 0.039 m M and it has good selectivity compared to other interfering substances.In electrochemical detection,when 3.0 m M H₂O₂ is present in the detection fluid,a rapid response is achieved within seconds.This work not only opens up an efficient way to improve the peroxidase-like activity of nanozymes,but also broadens the application scope of single-atom nanozymes.