Doping Nitrogen into Q-Graphene by Plasma Treatment toward Peroxidase Mimics with Enhanced Catalysis

Abstract

A facile and efficient plasma treatment strategy has been applied for the first time to dope heteroatom nitrogen (N) into Q-graphene (QG) under ambient temperature toward a carbon-based green nanozyme. It was discovered that the resulting N doped QG (N-QG) nanozyme can present the greatly enhanced catalysis activity, which is nearly 5-fold higher than that of pristine QG, as comparably revealed by the kinetic studies. Herein, the plasma treatment-assisted N doping could improve the conductivity (hydrophilicity) and create the surface defects of QG so as to promote the electron transferring toward the enhanced catalytic activities of N-QG. Furthermore, the catalase, superoxide dismutase, and oxidase-like catalysis activities of N-QG were explored, indicating the N doping could endow the obtained nanozyme with a high specificity of peroxidase-like catalysis. The application feasibility of the developed N-QG nanozyme was demonstrated subsequently by the catalysis-based colorimetric assays for H 2 O 2 in milk samples, with the linear range from 2.00 to 1500 μM. Importantly, such a plasma-assisted heteroatom doping route may open a door toward the large-scale applications for the rational designs of various enzyme mimics with improved catalysis performances.

Prospects of nano-carbons as emerging catalysts for enzyme-mimetic applications

“…The presence of diverse electronic configuration to doped nitrogen significantly influence the absorbance energy of intermediates and hence tune the selectivity of nanozymes. 51,74 In an innovative approach, compared to the pristine g-C 3 N 4 . 71 The another atom from the oxygen family is S which is contributing exceptionally towards the nanozyme activities.…”

Quality Assessment of Lactoferrin in some Marketed Nutraceuticals Derived from Milk using Validated Analytical Methods

“…Consequently heating milk at 90 °C at their natural pH significantly denatures most of the lactoferrin content and extensively reduced its biological efficacy. It worthy to say that, the presence of caseins, fat globules and polysaccharides in natural milk play good role at counteracting the effect of elevated temperature through the formation of intermolecular complex coacervate interaction with lactoferrin [17,18] . lactoferrin showed a high degree of stability when stored at temperature (2–8 °C) comparing to freshly prepared one [19] .…”

Recent Advances in Nanozymes: From Matters to Bioapplications

“…Wei et al proposed a new nitrogen‐doping strategy to fabricate highly active and specific POD‐like carbon nanozymes (Figure 10B). [ 161 ] They used a high nitrogen‐containing polymer as the nitrogen source and a natural clay mineral as a template, respectively. The current study not only provides a new strategy for fabricate POD‐like nanozymes, but also develops a facile assay to evaluate anti‐oxidant food quality and oxidative stress in healthcare.…”

“…Reproduced with permission. [ 161 ] Copyright 2019, American Chemical Society. C) Modified carbon nitride nanozyme as bifunctional glucose oxidase‐POD.…”