An enhanced sensitivity towards H2O2 reduction based on a novel Cu metal–organic framework and acetylene black modified electrode

•A novel Cu metal–organic framework (Cu-MOF) has been synthesized under hydrothermal condition.•The Cu-MOF modified electrode shows good electrocatalytic activity towards H2O2 reduction in alkaline solution.•The addition of acetylene black improves the response performance of the modified electrode towards H2O2 reduction.

As a large class of highly crystalline hybrid materials, metal-organic frameworks (MOFs) have the potentials to act as electrochemical sensors due to their active metal sites and diverse structures. However, the poor electron-conductive property limits their application as electrocatalyst. An effective strategy is to introduce conductive phases to the MOFs. In this paper, a novel Cu metal–organic framework {[Cu2(bep)(ada)2]·H2O}n (Cu-MOF) (beb = 1,4-bis(2-ethylbenzimidazol-1-ylmethyl) benzene, H2ada = 1,3-adamantanediacetic acid) was synthesized under hydrothermal condition. Single-crystal X-ray analysis revealed that the Cu-MOF was a three-dimensional pillar-layered framework with two kinds of paddle-wheel secondary building units. Subsequently, the Cu-MOF modified glassy carbon electrode (GCE) was applied in the H2O2 detection in alkaline solution, and it exhibited the good electrocatalytic activity towards H2O2 reduction. When acetylene black (AB) was added to the Cu-MOF, the electrocatalytic performance of the Cu-MOF modified electrode was greatly improved. The results of amperometric response to H2O2 with different AB addition showed that the Cu-MOF/AB-2%/GCE exhibited a wide linear relationship in the H2O2 concentration range of 0.05–3 μM with a rather high sensitivity of 5.56 μA μM−1 cm−2, a low detection limit of 0.014 μM as well as a fast response time of 4 s. The Cu-MOF/AB-2%/GCE also exhibited the good selectivity towards H2O2 reduction, and had no response to its normal co-existences of glucose, glycerin, alcohol and lactose. In addition, the modified electrode showed a good stability in the test period.