Oriented growth of cross-linked metal-organic framework film on graphene surface for non-enzymatic electrochemical sensor of hydrogen peroxide in disinfectant

High-density and cross-linked copper-based metal-organic framework (Cu-MOF) sheets were successfully prepared via a simple oriented growth method on a carboxylated graphene-modified electrode surface. Hydrogen peroxide (H 2 O 2 ) was selected as a model molecule to examine the performance of the thin film of Cu-MOF/graphene. The proposed sensor showed an extended linear detection range from 2.00 × 10 −7 to 1.85 × 10 −4 mol L −1 ( R = 0.998), a high sensitivity of 0.792 A (mol L −1 ) −1 , and a low detection limit of 6.7 × 10 −8 mol L −1 , due to the synergistic catalysis from the porous structure and favorable electron transfer mediating function of the electroactive Cu-MOFs and the high conductive property of the graphene. The reduction peak current of H 2 O 2 changed less than 3.7% in the presence of 57-fold high concentrations (2.0 × 10 −4 mol L −1 ) of the potential interfering species. The good selectivity of the prepared modified electrode was acquired by the size exclusion (molecular sieving) for H 2 O 2 because of the proper pore shape and pore size of Cu-MOFs. The feasibility of the assay was verified by test of H 2 O 2 in disinfectant samples. The proposed strategy presents valuable information related to the construction of non-enzymatic electrochemical sensors .