Metal-Free Carbon Nanozyme as Nicotinamide Adenine Dinucleotide Oxidase Mimic over a Broad pH Range for Coenzyme Regeneration

Abstract

Exploration of high-performance nanozymes for specific biomolecules is crucial but challenging for practical application. Nicotinamide adenine dinucleotide (NADH) oxidase can drive efficient regeneration of the oxidized coenzyme NAD + , which is of great significance for numerous NAD + -dependent biocatalytic pathways. However, issues including its instability and incompatibility with tandem enzymes in terms of pH, temperature, etc. remain to be addressed. Here, we report nitrogen-doped carbon materials templated from g-C 3 N 4 with NOX-like behaviors. The model s-NC nanozyme displays excellent catalytic activity in a wide pH range of 5.0−10.0 and a remarkable specific activity of up to 3.2 U/mg, which is superior to those of the reported NOX mimics. Furthermore, s-NC is coupled with natural dehydrogenases to develop a nanozyme−enzyme hybridization model for biosynthesis. Notably, it can well meet the pH requirement of the dehydrogenase under alkaline medium. This work not only develops NOX-mimicking metal-free nanozymes but also has inspired significance toward NAD + -mediated biosynthesis using artificial nanozymes.

Nanozyme‐Enhanced Electrochemical Biosensors: Mechanisms and Applications

“…In another work, Li et al developed nitrided carbon nanomaterials (s-NC) with mimetic NADH oxidase (NOX) activity for the specific biomolecule properties. [54] Further, by combining s-NC with natural dehydrogenase, a nanozyme−enzyme hybridization model for biosynthesis was developed to enable the representation of NOX-mimetic activity in alkaline medium. These works paved a promising way for the rational design and the performance enhancement of carbon-based non-metallic nanozymes, and broadened the mindset for novel nanozyme-mediated electrochemical assays.…”

Cyano-modified poly(triazine imide) with extended π-conjugation for photocatalytic biological cofactor regeneration

“…20,22 Additionally, PCN has advantages such as chemical stability, biocompatibility, and suitable band positions that satisfy NADH oxidation potential, making it a promising cofactor oxidation photocatalyst. 27 However, the photocatalytic activity of PCN is also severely restricted due to its amorphous structure, many defects in the bulk, and serious carrier recombination. In contrast to PCN, crystalline poly(triazine imide) (PTI) and poly(heptazine imide) (PHI) exhibit a more organized atomic structure and planar formation, leading to the extension of the π-conjugated plane.…”

Light-Driven Self-Cascade Peroxidase-like Nanozymes without Exogenous H2O2

“…Since the discovery of ferroferric oxide (Fe 3 O 4 ) nanoparticles with peroxidase (POD)-like activity, nanozymes have become an emerging field, due to the advantages of low cost, high stability, and strong tolerance to harsh conditions. , Up to now, numerous nanomaterials have shown enzyme-mimicking activity, including metal nanoparticles, − carbon materials, − and metal oxides. ,, Herein, POD-like nanozymes can catalyze the oxidation of chromogenic substrates by H 2 O 2 , , which have been used in the fields of biosensing, imaging, , and cancer treatment. , However, two major issues remain to be addressed, including the need for adding exogenous unstable H 2 O 2 and the relatively low affinity to H 2 O 2 , which is of great importance for the application of POD-like nanozymes. If the exogenous H 2 O 2 was avoided, the compatibility and stability of the catalytic system of POD-like nanozymes would significantly improve.…”