Heterojunction of Vertically Arrayed MoS₂ Nanosheet/N-Doped Reduced Graphene Oxide Enabling a Nanozyme for Sensitive Biomolecule Monitoring

Abstract

Enzymes are still indispensable for bio-assaying methods in biomolecule detection by far. The unsatisfied long-term instability, high cost, and susceptibility to the physical environment of natural enzymes are obvious weak points. Here, we developed peroxidase-like heterostructured nanozyme, vertically arraying molybdenum disulfide nanosheets on a substrate layer of nitrogen-doped reduced graphene oxide (MoS2/N-rGO), with a well-pleasing stability that is characterized by the retained enzymatic activity and maintained structure after 2 years of casual storage at ambient temperatures or 80 cycles of catalytic reaction. The catalytic kinetics of the as-prepared heterostructured nanozyme was superior to some reported nanozymes and even horse radish peroxidase, which was demonstrated due to the defect-rich MoS2 with Mo and S vacancies and nitrogen-doped rGO experimentally and theoretically. The vertically heterostructured nanozyme exhibited adequate analytical performance in sensitive and quantitative detection of glucose and glutathione (GSH), with a large dynamic sensing range and extremely low limit of detection (0.02 and 0.12 μM (3σ/slope) for glucose and GSH, respectively). We hope this inspired artificial nanozyme will contribute to the future development in sensitive detection of other biomolecules in physiological conditions.

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

“…Both theoretical and experimental studies have suggested that the defects created by molybdenum and sulfur in MoS 2 have enhanced the sensitivity and detection efficiency. 144 The one-pot synthesis method has been explored by Wang et could act as catalytic active sites. 145 Further, to enhance the activity of graphene the mesoporous Fe 3 O 4 has been incorporated and a 3D structure has been designed by Qiu et al for the detection of p-nitrophenol as it is an industrial effluent.…”

“…Both theoretical and experimental studies have suggested that the defects created by molybdenum and sulfur in MoS 2 have enhanced the sensitivity and detection efficiency. 144 The one-pot synthesis method has been explored by Wang et al for the synthesis of 3D graphene nanocomposites of Fe 3 O 4 . The 3D structure leads to the generation of channels and voids, which could act as catalytic active sites.…”

Single‐Atom Nanozymes for Biomedical Applications: Recent Advances and Challenges

“…As glucose and oxygen react enzymatically to create H 2 O 2 , nanozymes with peroxidase activity can then be applied to indirectly determine glucose levels [69] . Such as MoS 2 nanosheets/N‐atom‐doped graphene oxide, [70] Fe 3 O 4 /MW carbon nanotubes (CNTs), [71] etc., whereas SAzymes as more active nanozymes have also been investigated for application in more sensitive assays of glucose. Min Chen group [14] designed a single iron site nanozymes (Fe‐SSN) by a sacrificial carrier approach, where the porous structure of nitrogen‐doped carbon allows for a more dispersed but guaranteed number of iron sites to achieve higher peroxidase activity.…”

Combinational application of metal–organic frameworks‐based nanozyme and nucleic acid delivery in cancer therapy

“…MOFs are the ideal carriers for drug delivery because they can easily be modified with specific molecules and exhibit low toxicity, a large surface area, and nanoenzyme (or nanozyme)‐like properties (Cai et al, 2019; Ding et al, 2020; Sun et al, 2020). Nanozymes are a class of enzyme mimics that display both the unique properties of nanomaterials and the catalytic functions of enzymes (Cao et al, 2020; Duan et al, 2020; Fang et al, 2020; Gao et al, 2007; Wang, Chang, et al, 2020; Wang, Li, et al, 2021; Wang, Wang, et al, 2019; Wei et al, 2021; Zhou, Ouyang, et al, 2021; Zhou, You, et al, 2021).…”