In situ electrochemical reductive construction of metal oxide/metal-organic framework heterojunction nanoarrays for hydrogen peroxide sensing.

Transition metal oxide/metal-organic framework heterojunctions (TMO@MOF) that combine the large specific surface area of MOFs with TMOs' high catalytic activity and multifunctionality, show excellent performances in various catalytic reactions. Nevertheless, the present preparation approaches of TMO@MOF heterojunctions are too complex to control, stimulating interests in developing simple and highly controllable methods for preparing such heterojunction. In this study, we propose an in situ electrochemical reduction approach to fabricating CuO nanoparticle (NP)@CuHHTP heterojunction nanoarrays with a graphene-like conductive MOF CuHHTP (HHTP is 2,3,6,7,10,11-hexahydroxytriphenylene). We have discovered that size-controlled CuO nanoparticles could be in situ grown on CuHHTP by applying different electrochemical reduction potentials. Also, the obtained CuO NP@CuHHTP heterojunction nanoarrays show high HO sensitivity of 8150.6 μA·mM·cm and satisfactory detection performances in application of measuring HO concentrations in urine and serum samples. This study offers promising guidance for the synthesis of MOF-based heterojunctions for early cancer diagnosis.