In Situ Fabrication of Porous Nanostructures Derived from Bimetal-Organic Frameworks for Highly Sensitive Non-Enzymatic Glucose Sensors

Metal-organic framework (MOF) based porous derivatives have been attractive materials for high-performance electrochemical sensors due to their high surface-area, stability and activities. Herein, an in situ fabrication method is proposed to obtain porous Cu/Co bimetallic MOF-based derivatives on the flexible carbon cloth for glucose sensing. The process is also developed with three critical steps. Firstly, uniform Cu(OH)2 nanorods are directly formed through wet chemical method on Cu sputtered carbon cloth. Then, oriented growth of Zeolitic Imidazolate Framework-67 (ZIF-67) and ion-exchange convert the sample into Cu-Co-ZIF nanosheets. Finally, porous Cu-Co-ZIF derivatives are obtained by thermal annealing. The fabrication mechanism has been discussed through detailed characterizations of intermediate and final products. The as-obtained nanostructures with rich reaction sites and short ion diffusion path show excellent electrochemical properties for glucose sensing (high sensitivity of 18.68 mA mM-1 cm-2, fast response time of 1.5 s and low detection limit of 2 μM). This study proposes a practical fabrication strategy for bimetallic MOF-based porous nanostructures, which are promising for a wide variety of electrochemical applications.