Programmable and Reversible Regulation of Catalytic Hemin@MOFs Activities with DNA Structures

Metal-organic frameworks(MOFs)-based nanozyme plays an important role in biosensing, therapy and catalysis. In this study, the effects of single-stranded DNA(ssDNA) with programmable sequences and its complementary DNA(TDNA) on the intrinsic peroxidase-like activity of hemin loaded MOFs(UiO-66- 2 ), denoted as hemin@UiO-66-NH 2 , were investigated. The hemin@UiO-66- 2 exhibited improved catalytic activity compared with free hemin. However, the catalytic activity is inhibited in the presence of ssDNA, as ssDNA can be adsorbed by MOFs and therefore protected the active sites from contact with substrates. Upon the addition of the T DNA , double-stranded DNA(dsDNA) was formed and detached from the MOFs, resulting in the recovery of catalytic activity. Sequentially adding ssDNA or its complementary DNA strands can achieve the reversible regulation of the catalytic activity of MOFs nanozymes. Moreover, the DNA hybridization-based regulation was further applied to a cascaded catalytic system composed of the nanozyme, hemin@UiO-66-NH 2 , and glucose oxidase. These nanozyme based programmable and reversibly regulated catalytic systems may have potential applications in future smart biosensing and catalysis systems.