An electrochemical sensor for H2O2 based on a new Co-metal-organic framework modified electrode

In this work, a new Co metal-organic framework (Co(pbda)(4,4-bpy)center dot 2H2O](n)Co-MOF) (bpy =4,4-bipyridine; H(2)pbda = 3-(pyridine-3-yloxy)benzene-1,2-dicarboxylic acid) was synthesized under hydrothermal conditions and then applied as the active materials for high performance hydrogen peroxide sensor. Single-crystal X-ray analysis reveals a three-dimensional supramolecular architecture with a uninodal 4-connected net with the gis topology. The cyclic voltammogram of the Co-MOF modified GC electrode shows a pair of reduction peaks at ca. -0.40 V in 0.1 M NaOH solution corresponding to Co-III-OF/Co-II-MOF couple. The amperometric response demonstrates the high electrocatalytic activity of the Co-MOF modified GC electrode towards H2O2 reduction with a wide linear range from 5 mu M to 9.0 mM, a low detection limit of 3.76 mu M and a high sensitivity of 83.10 mu A mM(-1) cm(2) at an applied potential of -0.40 V. Moreover, the favourable selectivity and long-term stability were also obtained. Additionally, it was found that Co-MOF possessed highly efficient intrinsic peroxidase-like activity so that it could catalyze H2O2 to produce hydroxyl radical, which oxidized peroxidase substrate (terephthalic acid) to produce colour. Thus, this new Co-MOF has a great potential for applications in H2O2 electrochemical detection. (C) 2015 Elsevier B.V. All rights reserved.