Intercalation chemistry activates Co(OH)₂ for high-performance non-enzymatic glucose sensing via synergistic phase and microenvironment engineering.

The electrochemical inertness of conventional β-Co(OH)2 limits its application in non-enzymatic glucose sensing. Here, we demonstrate that MoO42- intercalation substantially activates Co(OH)2 by simultaneously triggering a crystallographic phase transformation from β to α phase and modulating the local electronic microenvironment. The intercalated anions expand the interlayer galleries, yielding a 1.7-fold enlargement of the electrochemically active surface area, withdraw electrons from Co centers to facilitate the generation of high-valent Co(Ⅲ)/Co(Ⅳ) active species at lowered potentials, and markedly strengthen glucose adsorption. Consequently, the MoO42--intercalated Co(OH)₂ achieves an ultrahigh sensitivity of 2743.9 µA mM-1 cm-2, which is 7.3 times that of pristine Co(OH)2, together with a wide linear range of 4.0 µM to 0.2 mM and a low detection limit of 0.36 µM. This work establishes an intercalation-driven dual-regulation strategy that integrates phase engineering and microenvironment modulation, offering a generalizable approach for the design of advanced sensing materials.