Magnetic iron oxide-based nanozymes: from synthesis to application

Abstract

Iron oxide nanozymes (IONzymes) are a class of magnetic nanoparticles that mimic the enzymatic activity of natural enzymes. These particles have received significant attention in recent years due to their unique properties, such as high stability, tunable magnetic responsiveness, and ability to act as biocatalysts for various chemical reactions. In this review, we aim to provide an overview of the production methods of magnetic nanozymes, including chemical, physical, and biological synthesis. The structure and design of magnetic nanozymes are also discussed in detail, as well as their applications in various fields such as biomedicine and environmental science. The results of various studies and the latest advances in the field of magnetic nanozymes are also discussed. This review provides valuable insights into the current state of magnetic nanozymes and highlights their potential for further development and application in various fields.

Fig. 1. Chemical and physical techniques for the synthesis of IONzymes.

Fig. 2. Suggested particle mechanism during the co-precipitation procedure: (1) particles are precipitated and agglomerated within 5 s, (2) agglomerated pieces grow over the next 2 or 3 min and (3) addition of neutralization solution causes particles to de-agglomerate within 10 min.

Fig. 3. Schematic representation of crystal growth mechanisms under hydrothermal/solvothermal conditions.

Fig. 4. Setup of the spray pyrolysis technique used for synthesis IONzymes thin film at various temperatures.

Fig. 5. Biosynthesis of IONzymes using different green sources.

Fig. 6. (a) Superparamagnetic iron oxide nanoparticles (SPIONs). (b) Face-centered cubic (FCC) closed packing, with Fe³⁺ in the tetrahedral sites and Fe²⁺ occupying the octahedral sites.

Fig. 7. Applications of IONzymes.

Fig. 8. Schematic presentation of nanozyme and aptamer-based immunosorbent assay (NAISA): (A) preparation of m-SAP/cDNA and (B) construction of NAISA for AFB1 detection.

Fig. 9. Schematic illustration of (A) investigation of dextran-coated Fe₃O₄ NPs in the liver, spleen, and lungs and (B) pH-dependent catalytic activity of ferumoxytol. (Insets) negative stain TEM of ferumoxytol (Scale bar: 50 nm and 10 nm for close image) and hydrodynamic diameter measurements. (C) Recoverable peroxidase-like Fe₃O₄@MoS₂-Ag nanozyme with enhanced antibacterial ability. (D) Multi-catalyst system for the quantification of galactose, entrapping both MNPs and Gal Ox in mesocellular silica.

Asma Ghazzy

Hamdi Nsairat

Rana Said

Obada A. Sibai

Aseel AbuRuman

Alaa S. Shraim

Afnan Al hunaiti