MOF-derived 3D leaf-like CuCo oxide arrays as an efficient catalyst for highly sensitive glucose detection

Abstract This work developed an effective MOF-template strategy to produce hierarchically structured leaf-like CuCo oxide 3D arrays on carbon cloth (CC/CuCo oxide). These subunits with different dimensionalities are homogeneously assembled into a unique hierarchical hollow and porous structure, which is good for increasing the surface area and exposing more catalytic sites. Besides, the successful integration of active nanomaterial and conductive CC substrate improves the conductivity, shortens the ion transmission path and accelerates the electron transfer at the electrode/electrolyte interface. The results demonstrate the effective active surface area of the self-supported CC/CuCo oxide-0.12 electrode can be increased 9.7 times with the unique hierarchical hollow architecture. When evaluated as electrocatalyst for glucose detection, the CC/CuCo oxide-0.12 electrode offers an ultrahigh sensitivity of 41.02 A M−1 cm−2, a low detection limit of 26 nM (3.3 σ/S), a short response time within 3 s, persistent stability and acceptable selectivity. Moreover, the sensor was successfully applied to the determination of glucose level in spiked human serum. Our results demonstrate a feasible method to prepare 3D CuCo oxide array with hierarchical hollow and porous structure, and pave a way to improve the performances of the nonenzymatic glucose sensor.