Fe-Coordinated Carbon Nanozyme Dots as Peroxidase-Like Nanozymes and Magnetic Resonance Imaging Contrast Agents

Abstract

The catalytic activities of currently developed peroxidase-mimic nanozymes are generally limited. Therefore, further efforts are still needed to improve the catalytic performance of peroxidase nanozymes. Herein, we synthesized Fe-coordinated carbon nanozyme dots (Fe-CDs) that can serve as both efficient peroxidase nanozymes and T 2 -magnetic resonance imaging (MRI) contrast agents. The intrinsic peroxidase-like activity of the Fe-CDs was explored by catalytic oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) with hydrogen peroxide (H 2 O 2 ). The product showed better performance over natural horseradish peroxidase (HRP) and other mimetic peroxidases. Quantification of glucose and ascorbic acid detection showed that this nanozyme could be used to detect a minimum limit as low as 5 μM glucose. Moreover, the colorimetric detection technique was used to detect serum glucose in mice, and the detection result was comparable with autobiochemistry analyzer results using a glucose assay kit. Furthermore, the Fe-CDs showed good magnetism properties and provided promising MR imaging of tumors with excellent biocompatibility.

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

“…The author has explored its magnetic property for bioimaging in MRI and checked the biocompatibility with U87MG and HepG2 cells. 168 32 generation, and autophagy was slightly increased, which helped in the removal of accumulated lipids (Fig. 11).…”

“…The author explored its magnetic property for bioimaging in MRI, and checked the biocompatibility with U87MG and HepG2 cells. 168 Li et al…”

“…The author explored its magnetic property for bioimaging in MRI, and checked the biocompatibility with U87MG and HepG2 cells. 168 Li et al studied the effect of Fe 3 C/N-doped graphitic carbon on the wound healing treatment. This nanozyme decomposes H 2 O 2 into the HO˙·radical, resulting in excessive ROS that leads to antibacterial activity, which accelerates wound healing.…”

Nanoscale Contrast Agents for Magnetic Resonance Imaging: A Review

“…Fe-coordinated carbon nanozyme dots were synthesized as T 2 -weighted MRI NCAs. These biocompatible quantum dots exhibited suitable magnetism characteristics, exhibiting attractive potentials for MRI of tumors . Ding et al introduced a single-atom Gd fastened onto graphene quantum dots with dendrite-like shape as NCAs for obtaining high-definition MRI, which need to be further explored for specific clinical theranostic applications.…”

The valine‐based N‐doped carbon dots with high peroxidase‐like activity

“…[ 2 ] These artificial mimics, including CeO 2 , [ 3 ] Fe 3 O 4 , [ 4 ] Co 3 O 4 , [ 5–8 ] MnO 2 [ 9,10 ] and MoS 2 nanaosheets, [ 11 ] show desirable peroxidase‐like activities similar to that of natural horseradish peroxidase (HRP). The high catalytic activity of these artificial mimics can result in favourable applications in biosensing, [ 12 ] early cancer diagnosis, [ 13 ] and removal of pollutants. [ 14 ] However, metal or metal oxide‐based nanomaterials in general require the acidic solution conditions used in catalytic reactions, severely limiting their applications in biological systems.…”