Polymeric Nanocapsule Enhances the Peroxidase-like Activity of Fe3O4 Nanozyme for Removing Organic Dyes

Abstract

Peroxidase-like nanozymes are nanoscale materials that can closely mimic the activity of natural peroxidase for a range of oxidation reactions. Surface coating with polymer nanogels has been considered to prevent the aggregation of nanozymes. For a long time, the understanding of polymer coating has been largely limited to its stabilization effect on the nanozyme in aqueous media, while little is known about how polymer coating plays a role in interaction with substrates and primary oxidants to dictate the catalytic process. This work reported a facile sequential modification of Fe3O4 nanoparticles to polyacrylamide coated nanozymes, and as low as 112 mg/L samples with only 5 mg/L Fe3O4 could nearly quantitatively (99%) remove a library of organic dyes with either H2O2 or Na2S2O8 as primary oxidants. The catalytic results and molecular simulation provide both experimental and computational evidence that the hydrogen bonding interaction between the reactant and nanozymes is key for the high local concentration hence catalytic efficiency. We envision that this work, for the first time, provides some insights into the role of polymer coating in enhancing the catalytic activity of nanozyme apart from the well-known water dispersity effect.

Nanozymes: powerful catalytic materials for environmental pollutant detection and degradation

“…On the one hand, many materials with peroxidase-like catalytic features have been utilized to fabricate Fenton-like systems to degrade these dyes. 44,[198][199][200][201][202][203][204][205][206][207][208][209][210][211][212][213][214][215] For example, Lin's group presented a strategy to construct graphene-gold nanoparticles (graphene/Au-NPs) through a one-step hydrothermal procedure, which acted as an effective scavenger for dyes with the synergetic impact of degradation and adsorption. 200 When different contents of the graphene/ Au-NPs material and H 2 O 2 (300 mM) were introduced to 10 μg mL −1 dye solutions, the remained dye levels were assessed by recording the supernatant's absorbance after removing graphene/Au-NPs.…”

Nanozyme as detector and remediator to environmental pollutants: between current situation and future prospective

“…The nanogel, composed of polyacrylamide with numerous amide groups, forms hydrogen bonds with IC, which contains two sulfonic groups. As the concentration of IC increases, the oxidation performance improves, and it is advisable to employ Fe 3 O 4 /Na 2 S 2 O 8 due to its greater strength, attributed to the extended half-life of sulfate radicals, which enhances their impact on the dyes (Zha et al 2022 ).…”

Recent advances in colorimetric sensors based on nanozymes with peroxidase-like activity

“…[5][6][7] Furthermore, nanozymes are less sensitive to pH and temperature changes than natural enzymes, and thus generally lead to more robust analytical assays. Thus far, great efforts have been devoted to developing various nanozymes, such as noble metals, 8,9 metal oxides, 10,11 metal sulfides/metal selenides, 12,13 carbon materials 14,15 and…”

“…5–7 Furthermore, nanozymes are less sensitive to pH and temperature changes than natural enzymes, and thus generally lead to more robust analytical assays. Thus far, great efforts have been devoted to developing various nanozymes, such as noble metals, 8,9 metal oxides, 10,11 metal sulfides/metal selenides, 12,13 carbon materials 14,15 and metal–organic frameworks (MOFs). 16–18 Various nanozymes have extremely broad application prospects in the fields of biosensing, immunoassay, and disease diagnosis.…”