Synchronous wrapping and inward-etching strategy on constructing yolk-shell MIL-88A@NiFe-PB heterostructures for electrochemical non-enzymatic glucose detection

Construction of heterocompositional hybrid metal-organic frameworks (MOFs) by integration of more than two MOFs is a smart strategy for fine-tuning MOF properties. In this work, a novel yolk-shell MIL-88A@NiFe-PB heterostructure, in which MIL stands for Materials from Institute Lavoisier, and PB represents the coordination network of Prussian Blue, was fabricated through a fast wrapping and then inward-etching growth synthetic strategy under mild stirring condition. The thickness of the outmost layer of NiFe-PB and the internal core structure of MIL-88A can be controlled by tuning the concentration of K-4[Fe(CN)(6)]3H(2)O in the assembly system. A rational growth mechanism for the yolk-shell MIL-88A@NiFe-PB heterostructure was proposed. The as-prepared yolk-shell MIL-88A@Ni10Fe PB-50 architectures were then explored for non-enzymatic glucose sensing. The results show that the designed glucose sensor exhibits a high sensitivity of 1963.2 mu A mM(-1) cm(-2) over a wide linear range of 0.005-1.0 mM, a low detection limit (0.12 mu M), as well as a fast reaction time (<2 s) and long-term stability for non-enzymatic glucose detection. Also, it shows good applicability in real serum samples. This work provides a "wrapping-inward-etching" synthetic strategy for construction of hybrid MOFs with exceptional outstanding non-enzymatic glucose sensing performance, providing a reasonable guide for construction of other MOF on MOF intriguing structures for electrochemical sensing applications.