Fe0/Fe3C-assisted Fe3O4 redox sites as robust peroxidase mimics for colorimetric detection of H2O2

Quantification of Neuronal Cell-Released Hydrogen Peroxide Using 3D Mesoporous Copper-Enriched Prussian Blue Microcubes Nanozymes: A Colorimetric Approach in Real Time and Anticancer Effect

“…Based on the hard–soft acid–base principles, it is evident that Fe 3+ is a stronger Lewis acid compared to Cu 2+ due to its larger radius and charge. TMB is a hard base with its amino site (−NH 2 ) and lone pair of electrons . The interaction between hard acids and hard bases is usually more favorable, while soft acids favor soft bases.…”

“…4 On the other hand, H 2 O 2 is commonly used as a preservative agent in the dairy sector, while the seafood industry employs it for processes such as bleaching and deodorization. 5 important to note that the excessive consumption of H 2 O 2 in food can be harmful to our bodies. Consequently, the Food and Drug Administration (FDA) recommends limiting H 2 O 2 use in food processing to 0.05%.…”

“…Magnetite nanoparticles (Fe 3 O 4 NPs) were among the first reported nanozymes to possess peroxidase-like (POD) activity alike horseradish peroxidase (HRP) . Since then, an array of nanostructures, including monometallic nanomaterials like Au NPs, Ag NPs, Pt NPs, and bimetallic nanoparticles such as Au@Ag nanorods, porous PtCu dendrites, Pt 74 Ag 26 , FePt–Au, metal oxides like MoS 2 , WS 2 , Co 3 O 4 , cerium oxide, as well as mixed metal oxides like Cr 2 O 2 –TiO 2 , ZnCo 2 O 4 , Fe 3 O 4 –Fe 0 /Fe 3 C, metal cluster nanomaterials like mercaptosuccinic acid (MSA)-stabilized Cu nanoclusters, and Fe–N/C single-atom nanozymes, along with metal–organic framework-based nanomaterials, , have found wide applications in colorimetric biosensors for detecting H 2 O 2 . However, these nanostructured materials exhibit certain drawbacks, such as complex synthesis processes and limited biocompatibility.…”

“…This has led to a search for more efficient CDT agents that can self-provide H 2 O 2 without the need for external energy input. The Fenton-type metal-based multivalent NPs such as Fe 2+ , Ce 3+ , Co 3+ , Cr 2+ , and Cu 2+ have shown excellent catalytic activity in recent studies, making them ideal for CDT nanoagents capable of supplying H 2 O 2 on demand. For instance, copper peroxide (CP) nanodots have been constructed to possess both Fenton-like and CAT-like activity for anticancer purposes .…”

Atomically dispersed Fe–Zn dual-site nanozymes with synergistic catalytic effects for the simultaneous detection of Cr(vi) and 8-hydroxyquinoline

“…The increase in peroxidase activity was mainly due to the weakened aggregation of Zn-NCs by the introduction of MWCNs, while the strong Lewis acidity of Fe 3+ had a good affinity for the chromogenic substrate TMB. 48,49 Therefore, we believe that the superior enzyme-like activity of MWCN/FeZn-NC is the result of the coordinated action of MWCNs, Zn-NCs, and Fe atoms.…”