Cu/Cu2O heterojunctions in carbon framework for highly sensitive detection of glucose

Abstract Metal/metal oxide heterojunctions with diverse combination is significantly desirable in constructing excellent electrochemical platform in the sensing field. In this paper, a ternary composite of Cu/Cu2O@C, in which a Cu/Cu2O heterojunctions with “head to head” combination fashion uniformly disperse in the octahedral carbon framework, is in situ generated by treating a copper-metal-organic framework (Cu-MOF) under a relatively mild temperature. The Cu/Cu2O@C composite is used as electrode material to modify glassy carbon electrode (GCE) to construct a glucose sensor, which shows excellent sensing behaviors with high detection sensitivities of 621.12 μA mM−1 cm−2 and 372.67 μA mM−1 cm−2 in the glucose concentration of 0.001–1.7 mM and 1.7–9.7 mM, respectively. Meanwhile, the Cu/Cu2O@C/GCE also exhibits outstanding selectivity for glucose as well as good stability, repeatability and practicability in the test process. The good sensing performances could attribute to the unique characteristics of Cu/Cu2O@C: (i) the highly dispersed Cu/Cu2O nanoparticles originating from metal-organic framework provide abundant catalytic-sites for the glucose oxidation; (ii) the “head to head” combination fashion for Cu/Cu2O heterojunctions make Cu and Cu2O fully participate in the electrocatalytic oxidation for glucose. (iii) the in situ generated carbon framework promotes the charge transfer in the electrocatalytic process.