Light-Mediated Modulation of Enzyme-Mimetic Activity of CuMnO₂ Nanosheets

Abstract

As typical copper-based-manganese delafossites, CuMnO 2 nanoflakes (CuMnO 2 NFs) display excellent light absorption capacity, showing great promise for facile regulation of catalysis reactions by light stimulation. Here, we report that the as-prepared CuMnO 2 NFs possess intrinsic peroxidase-and oxidase-like activities, which are capable of catalyzing the oxidation of the enzymatic substrate 3,3′,5,5′-tetramethylbenzidine (TMB) in the presence of H 2 O 2 or O 2 , respectively. Additionally, CuMnO 2 NFs exhibit significant lightenhanced dual enzyme-like performance (peroxidase and oxidase) for accelerating the oxidation of TMB, owing to a much greater light-induced reactive oxygen species (ROS) yield. The light-induced hydroxyl radicals (•OH) and superoxide radicals (O 2•− ) hold the key to rapidly catalyzing the oxidation of TMB into the two-electron charge transfer complex diamine, subsequently improving the oxidation capacity and enzyme-like activity of CuMnO 2 NFs as peroxidase and oxidase mimics. These findings confirm an efficient way to improve the enzyme-like performance of nanozymes and regulate the reactive oxygen species (ROS) level by simply employing irradiated light. This work also provides a general method for constructing external field-modulated smart nanozymes and an insightful approach to the corresponding enzyme-mimetic reaction mechanism.

Reusable CS-Ca@PEI/CuMnO2 Hydrogel Beads for Peroxymonosulfate-Activated Degradation of Congo Red

“…The distinctive diffraction peaks at 31.3°, 33.0°, 37.0°, 40.4°, 52.2°, 57.0°, and 59.3°correspond to the (002), ( 200), (111̅ ), ( 111), ( 202), (113̅ ), and (311̅ ) planes of CuMnO 2 , respectively. These peaks align well with literature reports, 40 confirming the crystalline nature of CuMnO 2 . The broad peak of 2θ = 16.8°was attributed to amorphous PEI.…”

Advances and perspectives of nanozymes in respiratory diseases

“…Among them, the explorations of metal oxide, metal, metal sulfide, carbon, and metalorganic frameworks have aroused remarkable interest. [42][43][44][45][46] Nanozymes with peroxidase-like activity can catalyze reactions of H 2 O 2 and H 2 O 2 -related substrates, widely applied for biosensors and biomedicine. [47][48][49][50][51] In these peroxidase-like nanozyme-catalyzed systems, substrates such as 3,3 0 ,5,5 0 -tetramethylbenzidine, 2,2 0 -azinobis-3-ethyl-benzothiazoline-6-sulfonic acid, o-phenylene-diamine dihydrochloride, Trinder's reagents, terephthalic acid, luminol, and others are often applied to generate signal products in the presence of H 2 O 2 .…”