3D Neighborhood Nanostructure Reinforces Biosensing Membrane

The electron signals in the cell can be rapidly and accurately transmitted by the spatially confined and adjacently distributed enzyme pairs anchored in the cytomembrane. As inspiration, by leverage of tannic acid-3-aminopropyltriethoxysilane-Fe (TA-APTES-Fe) ternary coating, for the first time, a mesoporous biosensing membrane is developed by orderly assembly and targeted confinement of Prussian blue (PB) and glucose oxidase (GOx) with neighborhood nanostructure in the 3D mesoporous carbon nanotubes (CNTs) membrane electrode. The mesoporous biosensing membrane extends the triple-phase boundary from conventional 2D contact to 3D contact, promotes the transfer rates of the cascade reactants, enhances the proximity of PB, GOx, and the electrode, and achieves in–situ removal of interferents, thereby elevating the utilization of PB, enhancing the cascade reaction efficiency, increasing the availability of the electroactive hydrogen peroxide (H₂O₂), and improving its stability. It exhibits superior sensitivity (31.2 µA mM⁻¹) and long-term stability in continuous glucose monitoring with a negligible response drift for up to 8 h. In addition, the multienzyme mimic functions of PB are employed to imitate the “loosening-degradation” membrane cleaning process via bubble scrubbing and Fenton oxidation, thereby fully regenerating the fouled biosensing membrane. This work provides a novel design strategy for biosensors toward efficient, reliable, and stable sensing.