Original Pan XX Antibacterial Technology Circle
First author: Sk Rajab Ali
Component author: Mrinomy De
Component unit: Indian Institute of Science and Technology
Research quick look
Recently, Mrinomy De research team from Indian Institute of Science and Technology was in ACS Applied Materials & Research on the antibacterial and detoxification activity of Fe doped MoS2 nanoenzyme on mustard gas simulated agent was published on Interfaces. The peroxidase -like catalytic activity of various nanoenzyme is widely used in various fields. In this study, the authors prepared Fe-doped MoS2 (Fe@MoS2) nanomaterials with enhanced MoS2 peroxidase-like activity through a cocatalytic pathway. Using the Fenton reaction, the peroxidase-like Fe@MoS2 nanoenzymes stimulated the decomposition of hydrogen peroxide (H2O2) into active hydroxyl radicals (·OH). The effect of efficient decomposition of H2O2 on the antibacterial and detoxification activity of mustard gas simulaters in the presence of Fe@MoS2 was studied. Under the action of low concentration of H2O2, Fe@MoS2 and H2O2 combined action has significant antibacterial activity on methicillin-resistant Staphylococcus aureus and E. coli . Fe@MoS2 is further applied to the detoxification of the chemical warfare agent sulfur mustard simulated agent 2-chloroethyl ethyl sulfide, and selected to convert it into non-toxic sulfoxide . This work demonstrates the development of a hybrid nanoenzyme and its environmental restoration from harmful chemicals to microorganisms.
Key points analysis
Key points 1. improves the catalase activity of MoS2 by doping Fe: the peroxidase-like catalytic activity of Fe@MoS2. Fe ions doped on the MoS2 lattice plane significantly improve the activity of peroxidase-like nanoenzymes in the cocatalytic pathway. The obtained MoS2 has a very high Kcat value compared to many other reported nanoenzymes (1.6 × 10−2 M s−1 g−1).
Key points 2, reflecting the antibacterial performance of : Fe@MoS2 high peroxidase-like activity has high antibacterial activity against the Gram-positive drug-resistant pathogenic pathogens methicillin-resistant Staphylococcus aureus (MRSA) and the Gram-negative strain E. coli. In the presence of highly diluted H2O2 (~17650-fold), Fe@MoS2 nanomaterial showed significant bactericidal activity for both strains. Fe@MoS2 nanomaterial also has a good detoxification effect on mustard simulated agents in the presence of H2O2.
Graphics and text introduction
Figure 1. Characterization of Fe@MoS2 nanomaterials synthesized by . (a) SEM images of Fe@MoS2 nanomaterials are shown as clustered flower-like structures. (b) The TEM image of Fe@MoS2 shows the approximate size of a single nanoflower , about 220 nanometers. (c) HRTEM images of Fe@MoS2 nanomaterials show d-spacing between adjacent layers. (d) The XPS broad spectrum of Fe@MoS2 nanomaterial represents the overall composition. The XPS spectrum of (e) Mo 3d, (f) S 2p and (g) Fe 2p indicate that there are related elements in the Fe@MoS2 heterostructure. (h) XRD maps of original MoS2 and Fe@MoS2 nanomaterials indicate the presence of MoS2 layers in the composite material. (i) The magnetization pattern of MoS2 and Fe@MoS2 nanomaterials represents the magnetism of the nanomaterials.
Figure 2. (a) Reaction scheme for Fe@MoS2 peroxidase-like catalytic activity. (b) UV-visible map of Fe@catalytic activity
in acetic acid buffer medium present in H2O2 (2.5 mM) and TMB (0.5 mM), MoS2 (6.25 μg/mL) and native MoS2 (6.25 μg/mL) (100 mM, pH = 4.2) for 30 min.
Figure 3. (a) The mechanism of cocatalytic reaction pathway of peroxidase-like nanoenzyme activity of Fe@MoS2 nanomaterials is proposed. (b) High resolution XPS spectroscopy of doped Fe atoms in Fe@MoS2 nanomaterials indicate the presence of two oxidation states. (c) Reaction scheme for oxidizing TA by hydroxy radical (·OH). (d) Detection of hydroxyl radicals (·OH) by TA method. In acetic acid buffer (0.1 M, pH = 4.2) medium in the presence of TA (0.5 mM), H2O2 (5 mM), Fe@MoS2 (1.25 μg/mL) and other control substances. The fluorescence emission spectrum was recorded at the excitation wavelength of 315 nm.
Figure 4.Agar plate images of colonies formed by MRSA and E. coli strainsAfter treatment, Fe@MoS2 nanoenzyme was cultured at concentrations of 2.5 and 1.25 μg/mL, respectively, in acetic acid buffer medium (100 mM, pH = 4.2) containing H2O2 (0.5 mM, 1.7 × 10−3%), Fe@MoS2 nanoenzyme was cultured at concentrations of 2.5 and 1.25 μg/mL for 1 h, respectively.
Figure 5. (a) Reaction scheme for nanoenzyme catalyzed oxidation of CEES. (b) GC graph of CEES conversion over time. (c) Transformation diagram of oxidation of CEES (25 mg, 0.2 mmol) to CEESO in the presence of Fe@MoS2 (100 μg) and H2O2 to CEESO at room temperature
(0.21 mmol)methanol (MeOH, 2 mL) at room temperature. (d) Hydrogen NMR analysis of catalytic oxidation products.
Conclusion
This paper reports the preparation of Fe@MoS2 nanomaterials as an efficient peroxidase nanoenzyme and applied to the antibacterial activity and detoxification of sulfur mustard. Since iron ion is inserted into the MoS2 layer, the catalytic activity of MoS2 is significantly enhanced. This significant enhancement comes from the synergistic effect of Fe and MoS2 cocatalytic activity and the inherent characteristics of the MoS2 layer. Similar methods can be extended to other metal ion and nanomaterial composites to enhance the activity of nanoenzymes. This enhanced activity has been rarely studied in the application of antibacterial activity and has never been applied to the detoxification of CWAs. The authors demonstrated that in the presence of the nanoenzyme Fe@MoS2, the disinfectant H2O2 showed very high bactericidal effect on drug-resistant strains MRSA and E. coli at the lowest concentrations previously reported. In addition, the use of peroxidase-like nanoenzymes to detoxify sulfur mustard gas has not been used. The author has a good control effect on the catalytic oxidation of simulated mustard gas CEES, without any toxic peroxidation. Therefore, this study will help explore the development of novel peroxidase nanoenzymes and their applications in environmental restoration.
Full-text link: https://doi.org/10.1021/acsami.2c11245
References: Ali, S. R.; De, M., Fe-Doped MoS2 Nanozyme for Antibacterial Activity and Detoxification of Mustard Gas Simulant. ACS Applied Materials & Interfaces 2022, DOI: org/10.1021/acsami.2c11245
Submission Contact: [email protected]
