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1.
Inorg Chem ; 63(20): 9058-9065, 2024 May 20.
Article in English | MEDLINE | ID: mdl-38720438

ABSTRACT

Nitrofurans are important synthetic broad-spectrum antibacterial drugs with the basic structure of 5-nitrofuran. Due to their toxicity, it is essential to develop a sensitive sensor with strong anti-interference capabilities for their detection. In this work, two {P4Mo6O31}12--based compounds, [H4(HPTTP)]2{CuI[Mo12O24(OH)6(PO4)3(HPO4)(H2PO4)4]}·xH2O (x = 13 for (1), 7 for (2); HPTTP = 4,4',4″,4‴-(1H-pyrrole-2,3,4,5-tetrayl)tetrapyridine), exhibiting similar coordination but distinct stacking modes. Both compounds were synthesized and used for the electrochemical detection of nitrofuran antibiotics. The tetrapyridine-based ligand was generated in situ during assembly, and its potential mechanism was discussed. Composite electrode materials, formed by mixing graphite powder with compounds 1-2 and physically grinding them, proved to be highly effective in the electrochemical trace detection of furazolidone (FZD) and furaltadone hydrochloride (FTD·HCl) under optimal conditions. Besides, the possible electrochemical detection mechanisms of two nitro-antibiotics were studied.


Subject(s)
Anti-Bacterial Agents , Coordination Complexes , Copper , Nitrofurans , Polymers , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/analysis , Ligands , Nitrofurans/analysis , Nitrofurans/chemistry , Copper/chemistry , Copper/analysis , Coordination Complexes/chemistry , Coordination Complexes/chemical synthesis , Polymers/chemistry , Molybdenum/chemistry , Pyridines/chemistry , Molecular Structure , Electrochemical Techniques , Models, Molecular
2.
Chemosphere ; 358: 142237, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38705406

ABSTRACT

In this study, a novel Ce2MgMoO6/CNFs (cerium magnesium molybdite double perovskite decorated on carbon nanofibers) nanocomposite was developed for selective and ultra-sensitive detection of ciprofloxacin (CFX). Physical characterization and analytical techniques were used to explore the morphology, structure, and electrocatalytic characteristics of the Ce2MgMoO6/CNFs nanocomposite. The sensor has a wide linear range (0.005-7.71 µM and 9.75-77.71 µM), a low limit of detection (0.012 µM), high sensitivity (0.807 µA µM-1 cm-2 nM), remarkable repeatability, and an appreciable storage stability. Here, we used density functional theory to investigate CFX and oxidized CFX as well as the locations of the energy levels and electron transfer sites. Furthermore, the Ce2MgMoO6/CNFs-modified electrode was successfully tested in food samples (milk and honey), indicating an acceptable response with a recovery percentage and relative standard deviation of less than 4%, which is comparable to that of GC-MS. Finally, the developed sensor exhibited high selectivity and stability for CFX detection.


Subject(s)
Carbon , Ciprofloxacin , Honey , Milk , Nanocomposites , Nanofibers , Oxides , Nanocomposites/chemistry , Ciprofloxacin/analysis , Ciprofloxacin/chemistry , Oxides/chemistry , Milk/chemistry , Nanofibers/chemistry , Animals , Honey/analysis , Carbon/chemistry , Molybdenum/chemistry , Limit of Detection , Calcium Compounds/chemistry , Titanium/chemistry , Density Functional Theory , Electrochemical Techniques/methods , Cerium/chemistry , Food Contamination/analysis , Electrodes , Magnesium/chemistry , Magnesium/analysis
3.
Biosens Bioelectron ; 257: 116345, 2024 Aug 01.
Article in English | MEDLINE | ID: mdl-38692247

ABSTRACT

Nitrite (NO2-) is present in a variety of foods, but the excessive intake of NO2- can indirectly lead to carcinogenic, teratogenic, mutagenicity and other risks to the human body. Therefore, the detection of NO2- is crucial for maintaining human health. In this study, an integrated array sensor for NO2- detection is developed based on molybdenum single atom material (IMSMo-SAC) using high-resolution electrohydrodynamic (EHD) printing technology. The sensor comprises three components: a printed electrode array, multichannels designed on polydimethylsiloxane (PDMS) and an electronic signal process device with bluetooth. By utilizing Mo-SAC to facilitate electron transfer during the redox reaction, rapid and efficient detection of NO2- can be achieved. The sensor has a wide linear range of 0.1 µM-107.8 mM, a low detection limit of 33 nM and a high sensitivity of 0.637 mA-1mM-1 cm-2. Furthermore, employing this portable array sensor allows simultaneously measurements of NO2- concentrations in six different foods samples with acceptable recovery rates. This array sensor holds great potential for detecting of small molecules in various fields.


Subject(s)
Biosensing Techniques , Equipment Design , Food Analysis , Limit of Detection , Molybdenum , Nitrites , Molybdenum/chemistry , Biosensing Techniques/instrumentation , Nitrites/analysis , Food Analysis/instrumentation , Humans , Dimethylpolysiloxanes/chemistry , Electrodes , Electrochemical Techniques/methods , Electrochemical Techniques/instrumentation , Food Contamination/analysis
4.
Anal Methods ; 16(20): 3278-3286, 2024 May 23.
Article in English | MEDLINE | ID: mdl-38738557

ABSTRACT

Dextromethorphan (DXM) is a widely utilized central antitussive agent, which is frequently abused by individuals seeking its recreational effect. But DXM overdose can cause some adverse effects, including brain damage, loss of consciousness, and cardiac arrhythmias, and hence its detection is significant. Herein, an electrochemical sensor based on a Cu-coordinated molecularly imprinted polymer (Cu-MIP) was fabricated for its detection. For constructing the sensor, nitrogen-doped carbon nanosheets (CCNs) were prepared through calcining chitin under an argon atmosphere, and molybdenum disulfide (MoS2) was allowed to grow on their surface. Subsequently, the obtained MoS2/CCNs composite was employed to modify a glassy carbon electrode (GCE), and the Cu-MIP was electrodeposited on the electrode in a Cu-1,10-phenanthroline (Cu-Phen) solution containing DXM, where Cu2+ played a role in facilitating electron transfer and binding DXM. Due to the large specific surface area, good electrocatalytic properties and recognition of the resulting composite, the resulting Cu-MIP/MoS2/CCNs/GCE showed high selectivity and sensitivity. Under optimized experimental conditions, the peak current of DXM and its concentration exhibited a good linear relationship over the concentration range of 0.1-100 µM, and the limit of detection (S/N = 3) was 0.02 µM. Furthermore, the electrochemical sensor presented good stability, and it was successfully used for the determination of DXM in pharmaceutical, human serum and urine samples.


Subject(s)
Carbon , Copper , Dextromethorphan , Disulfides , Electrochemical Techniques , Molecularly Imprinted Polymers , Molybdenum , Molybdenum/chemistry , Disulfides/chemistry , Dextromethorphan/analysis , Dextromethorphan/chemistry , Dextromethorphan/urine , Copper/chemistry , Electrochemical Techniques/methods , Carbon/chemistry , Molecularly Imprinted Polymers/chemistry , Chitin/chemistry , Humans , Limit of Detection , Electrodes , Antitussive Agents/chemistry , Antitussive Agents/analysis , Antitussive Agents/urine
5.
Sci Rep ; 14(1): 11206, 2024 05 16.
Article in English | MEDLINE | ID: mdl-38755178

ABSTRACT

Contamination of soils by Molybdenum (Mo) has raised increasing concern worldwide. Both fulvic acid (FA) and humic acid (HA) possess numerous positive properties, such as large specific surface areas and microporous structure that facilitates the immobilization of the heavy metal in soils. Despite these characteristics, there have been few studies on the microbiology effects of FA and HA. Therefore, this study aimed to assess the Mo immobilization effects of FA and HA, as well as the associated changes in microbial community in Mo-contaminated soils (with application rates of 0%, 0.5% and 1.0%). The result of the incubation demonstrated a decrease in soil pH (from 8.23 ~ 8.94 to 8.05 ~ 8.77). Importantly, both FA and HA reduced the exchangeable fraction and reducible fraction of Mo in the soil, thereby transforming Mo into a more stable form. Furthermore, the application of FA and HA led to an increase in the relative abundance of Actinobacteriota and Firmicutes, resulting in alterations to the microbial community structure. However, it is worth noting that due to the differing structures and properties of FA and HA, these outcomes were not entirely consistent. In summary, the aging of FA and HA in soil enhanced their capacity to immobilization Mo as a soil amendment. This suggests that they have the potential to serve as effective amendments for the remediation of Mo-contaminated soils.


Subject(s)
Humic Substances , Metals, Heavy , Soil Microbiology , Soil Pollutants , Humic Substances/analysis , Soil Pollutants/chemistry , Benzopyrans/chemistry , Benzopyrans/pharmacology , Molybdenum/chemistry , Soil/chemistry , Hydrogen-Ion Concentration , Bacteria/drug effects , Microbiota/drug effects
6.
Int J Mol Sci ; 25(9)2024 Apr 29.
Article in English | MEDLINE | ID: mdl-38732078

ABSTRACT

This study aimed to synthesize molybdenum complexes coordinated with an aroyl hydrazone-type ligand (H2L), which was generated through the condensation of 2-hydroxy-5-nitrobenzaldehyde with benzhydrazide. The synthesis yielded two types of mononuclear complexes, specifically [MoO2(L)(MeOH)] and [MoO2(L)(H2O)], as well as a bipyridine-bridged dinuclear complex, [(MoO2(L))2(4,4'-bpy)]. Those entities were thoroughly characterized using a suite of analytical techniques, including attenuated total reflectance infrared spectroscopy (IR-ATR), elemental analysis (EA), thermogravimetric analysis (TGA), and single-crystal X-ray diffraction (SCXRD). Additionally, solid-state impedance spectroscopy (SS-IS) was employed to investigate the electrical properties of these complexes. The mononuclear complexes were tested as catalysts in the epoxidation of cyclooctene and the oxidation of linalool. Among these, the water-coordinated mononuclear complex, [MoO2(L)(H2O)], demonstrated superior electrical and catalytic properties. A novel contribution of this research lies in establishing a correlation between the electrical properties, structural features, and the catalytic efficiency of the complexes, marking this work as one of the pioneering studies in this area for molybdenum coordination complexes, to the best of our knowledge.


Subject(s)
Benzaldehydes , Coordination Complexes , Molybdenum , Oxidation-Reduction , Molybdenum/chemistry , Catalysis , Coordination Complexes/chemistry , Benzaldehydes/chemistry , Semiconductors
7.
Bioresour Technol ; 401: 130761, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38692370

ABSTRACT

Cr (VI) is a common heavy metal pollutant in electroplating wastewater. This study introduces the liquid-phase product from the hydrothermal reaction of coffee grounds (CGHCL) into the synthesis process of molybdenum disulfide, assisting in the fabrication of an intercalated, expanded core-shell structured molybdenum disulfide adsorbent (C-MoS2), designed for the adsorption and reduction of Cr (VI) from electroplating wastewater. The addition of CGHCL significantly enhances the adsorption performance of MoS2. Furthermore, C-MoS2 exhibits exceedingly high removal efficiency and excellent regenerative capability for Cr (VI)-containing electroplating wastewater. The core-shell structure effectively minimizes molybdenum leaching to the greatest extent, while the oleophobic interface is unaffected by oily substances in water, and the expanded interlayer structure ensures the long-term stability of C-MoS2 in air (90 days). This study provides a viable pathway for the resource utilization of biomass and the application of molybdenum disulfide-based materials in wastewater treatment.


Subject(s)
Biomass , Chromium , Disulfides , Molybdenum , Wastewater , Water Purification , Molybdenum/chemistry , Disulfides/chemistry , Adsorption , Wastewater/chemistry , Water Purification/methods , Chromium/chemistry , Electroplating , Water Pollutants, Chemical , Solutions
8.
Chemosphere ; 358: 142094, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38648984

ABSTRACT

Designing of an effectual heterostructure photocatalyst for catalytic organic pollutant exclusion has been the subject of rigorous research intended to resolve the related environmental aggravation. Fabricating p-n junctions is an effective strategy to promote electron-hole separation of semiconductor photocatalysts as well as enhance the organic toxin degradation performance. In this study, a series of n-type NiAlFe-layered triple hydroxide (LTH) loaded with various ratios of p-type MoS2 was synthesized for forming a heterostructure LTH/MoS2 (LMs) by an in situ hydrothermal strategy. The photocatalysts were characterized by XRD, SEM&EDX, TEM, FT-IR, XPS, as well as UV-vis DRS. The photoactivity of photocatalysts was tested by the degradation of Indigo Carmine (IC) dye. The optimized catalyst (LM1) degrades 100% of indigo dye in high alkaline pH under UV light for 100 min. Besides, the degradation rate of LM1 is 15 times higher than that of pristine NiAlFe-LTH. The enhanced photoactivity is attributed to the synergistic effect between NiAlFe-LTH and MoS2 as well as the p-n junction formation.


Subject(s)
Coloring Agents , Indigo Carmine , Molybdenum , Catalysis , Coloring Agents/chemistry , Molybdenum/chemistry , Indigo Carmine/chemistry , Disulfides/chemistry , Hydrogen-Ion Concentration , Light , Water Pollutants, Chemical/chemistry , Hydroxides/chemistry , Photolysis , Ultraviolet Rays
9.
Chemosphere ; 358: 142157, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38679181

ABSTRACT

Microbial electrosynthesis (MES) is an electrically driven technology that can be used for converting CO/CO2 into chemicals. The unique electronic and substrate properties of CO make it an important research target for MES. However, CO can poison the cathode and increase the overpotential of hydrogen evolution reaction (HER), thus reducing the electron transfer rate via H2. This work evaluated the effect of an anti-CO HER catalyst on the performance of MES for CO/CO2 conversion. ZnMo-metal-organic framework (MOF) materials with different calcination temperatures were synthesized. ZnMo-MOF-800 with Mo2C nanoparticles as active centers exhibited excellent resistance to CO toxicity. It also obtained the highest hydrogen evolution and enhanced electron transfer rate in CO atmosphere. MES with ZnMo-MOF-800 cathode and Clostridium ljungdahlii as biocatalyst obtained 0.31 g L-1 d-1 acetate yield, 0.1 g L-1 d-1 butyrate yield, and 0.09 g L-1 d-1 2,3-butanediol yield in CO/CO2, while Pt/C only get 0.076 g L-1 d-1 acetate yield, 0.05 g L-1 d-1 butyrate yield and 0.02 g L-1 d-1 2,3-butanediol yield. ZnMo-MOF-800 was conducive to biofilm formation, enabling it to better resist CO toxicity. This work provides new opportunities for constructing a highly efficient cathode with an anti-CO hydrogen evolution catalyst to enhance CO/CO2 conversion in MES.


Subject(s)
Carbon Dioxide , Carbon Monoxide , Hydrogen , Metal-Organic Frameworks , Hydrogen/metabolism , Hydrogen/chemistry , Carbon Dioxide/chemistry , Catalysis , Metal-Organic Frameworks/chemistry , Electrodes , Clostridium/metabolism , Electrochemical Techniques , Molybdenum/chemistry , Zinc/chemistry
10.
Environ Pollut ; 350: 124019, 2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38663506

ABSTRACT

Lead(II) is a potential carcinogen of heavy-metal ions (HIs). With the wide application of Pb-bearing products including lead alloy products, and new-energy lead-ion batteries, lead pollution has become a tricky problem. To solve such a difficulty, novel ultrathin MoS2-vinyl hybrid membranes (MVHMs) with a "spring" effect were synthesized via co-polymerization of acrylic acid, styrene and molybdenum disulfide (MoS2) and their adsorptions for HIs were explored. The "spring" effect derived from the interaction between the tendency of the short polyacrylic acid (PAA) chain connected with MoS2 to spread outward and the coulomb force between layers from MoS2 (s-MoS2), which enlarge the spacing of MoS2 layers without changing the number of layers after membrane formation, which changes the swelling membrane to a dense membrane and reduces the original thickness from 0.5 cm to 0.011 mm in the thickness direction. The adsorption experiment revealed that these MVHMs had super adsorption performance and high selectivity for Pb2+ by comparison with other five metal ions: Cu2+, Cd2+, Ni2+, Cr3+ and Zn2+. Especially, the adsorption quantity of MVHMs for Pb2+ could approach 2468 mg/g and the maximum adsorption ratio of qe[Pb2+]/qe[Cu2+] can reach 10.909. These values were much larger than the data obtained with the adsorbents reported in the last decade. A variety of models are applied to evaluate the effect of ionic groups. It was confirmed that -COOH plays a key role in adsorption of HIs and s-MoS2 also has a certain contribution. Conversely, ion exchange plays only a minor role during the period of adsorption process. Effective diffusion coefficient (Deff) of Pb(II) had the largest values among these metal ions. Hence, these hybrid membranes are promising adsorbents for the removal of Pb2+ from water containing various ions.


Subject(s)
Acrylates , Disulfides , Lead , Molybdenum , Styrene , Molybdenum/chemistry , Lead/chemistry , Adsorption , Acrylates/chemistry , Disulfides/chemistry , Styrene/chemistry , Polymerization , Membranes, Artificial , Water Pollutants, Chemical/chemistry , Metals, Heavy/chemistry
11.
J Chromatogr A ; 1722: 464843, 2024 May 10.
Article in English | MEDLINE | ID: mdl-38574599

ABSTRACT

Reversed-phase high performance liquid chromatography (RP-HPLC) is the most widely used chromatographic method. In addition to hydrophobic interactions, additional interactions such as electrostatic interactions may participate in the retention behaviour of an analyte. This makes it possible to use RP-HPLC for many types of analyte. We describe a simple method for separating inorganic anions on a C18 column, in which retention of inorganic anions is almost entirely due to electrostatic interactions. This leads to rapid separations as well as higher theoretical plate numbers. We used 2 mM phosphoric acid containing a low concentration of disodium molybdate as the mobile phase, which allows UV detection of non-UV-absorbing anions. With this method, we determined eight inorganic anions including several non-UV-absorbing anions photometrically at 220 nm. The detection limits of the examined eight inorganic anions calculated at a signal-to-noise ratio of 3 were between 0.3 and 10 µM. The detector response was linear over three orders of magnitude of inorganic anion concentration. The proposed RP-HPLC/UV method was successfully applied to determine inorganic anions in some water samples.


Subject(s)
Anions , Chromatography, Reverse-Phase , Molybdenum , Phosphoric Acids , Anions/chemistry , Molybdenum/chemistry , Phosphoric Acids/chemistry , Chromatography, Reverse-Phase/methods , Chromatography, High Pressure Liquid/methods , Limit of Detection
12.
Chemosphere ; 357: 142033, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38615961

ABSTRACT

The design and preparation of dual-functional photocatalysts for simultaneously realizing photocatalytic wastewater purification and hydrogen energy generation pose significant challenges. This article presents the engineering of a binary heterostructured photocatalyst by combining TiO2 (nanorods) and MoS2 nanosphere using a straightforward solvothermal method and the assessment of the phase structures, morphologies, and optical properties of the resulting nanocomposites using diverse analytical techniques. The TiO2(Rod)/MoS2 composite exhibits remarkable efficacy in degrading ciprofloxacin, achieving 93% removal rate within 1 h, which is four times higher than that of bare TiO2. Moreover, the optimized TiO2(Rod)/MoS2 presents an outstanding hydrogen production rate of 7415 µmol g-1, which is ∼24 times higher than that of pristine TiO2. Under UV-visible light irradiation, the TiO2(Rod)/MoS2 heterojunction displays an exceptional photocatalytic performance in terms of both photodegradation and hydrogen production, surpassing the performance of TiO2 particle/MoS2. The study findings demonstrate that TiO2(Rod)/MoS2 nanocomposites exhibit considerably improved photocatalytic degradation and hydrogen generation activities. Based on the experimental results, a possible mechanism is proposed for the transfer and separation of charge carriers in Z-scheme heterojunctions.


Subject(s)
Anti-Bacterial Agents , Disulfides , Hydrogen , Molybdenum , Nanospheres , Nanotubes , Titanium , Titanium/chemistry , Molybdenum/chemistry , Catalysis , Anti-Bacterial Agents/chemistry , Nanospheres/chemistry , Hydrogen/chemistry , Disulfides/chemistry , Nanotubes/chemistry , Nanocomposites/chemistry , Photolysis , Water Pollutants, Chemical/chemistry , Wastewater/chemistry , Ciprofloxacin/chemistry
13.
Chemosphere ; 357: 141965, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38621491

ABSTRACT

In this work, we report a supercapacitor electrode material based on nano-flower like cobalt molybdate decorated on porous activated carbon derived from waste onion peels (ß-CoMoO4-POAC). The obtained POAC exhibits highly porous structure and after the hydrothermal treatment with salts of cobalt and molybdenum, we observed a uniform distribution of ß-cobalt molybdate (ß-CoMoO4) as nano-flowers on the surface of POAC. The chemical composition, morphology and porosity of the materials were thoroughly analyzed using field emission scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, infrared spectroscopy and Brunauer-Emmet-Teller surface area measurement. Due to its flower like and highly porous morphology, ß-CoMoO4@POAC exhibits a high specific capacitance of 1110.72 F/g at a current density of 1 mA/cm2 with superior cyclic retention of 96.03% after 2000 cycles. The best electrochemical performance exhibited by ß-CoMoO4@POAC is mainly due to its high surface area and porous nature of the material which assists in active transport of ions. This study reveals the exceptional electrochemical properties of ß-CoMoO4@POAC which could be considered as a potential material for advanced energy storage devices.


Subject(s)
Cobalt , Electric Capacitance , Electrodes , Molybdenum , Nanocomposites , Molybdenum/chemistry , Cobalt/chemistry , Nanocomposites/chemistry , Porosity , Charcoal/chemistry , Carbon/chemistry
14.
Int J Mol Sci ; 25(8)2024 Apr 17.
Article in English | MEDLINE | ID: mdl-38674003

ABSTRACT

A novel photocatalytic nanomaterial, Ho2YSbO7, was successfully synthesized for the first time using the solvothermal synthesis technique. In addition, a Ho2YSbO7/Bi2MoO6 heterojunction photocatalyst (HBHP) was prepared via the hydrothermal fabrication technique. Extensive characterizations of the synthesized samples were conducted using various instruments, such as an X-ray diffractometer, a Fourier transform infrared spectrometer, a Raman spectrometer, a UV-visible spectrophotometer, an X-ray photoelectron spectrometer, and a transmission electron microscope, as well as X-ray energy dispersive spectroscopy, photoluminescence spectroscopy, a photocurrent test, electrochemical impedance spectroscopy, ultraviolet photoelectron spectroscopy, and electron paramagnetic resonance. The photocatalytic activity of the HBHP was evaluated for the degradation of diuron (DRN) and the mineralization of total organic carbon (TOC) under visible light exposure for 152 min. Remarkable removal efficiencies were achieved, with 99.78% for DRN and 97.19% for TOC. Comparative analysis demonstrated that the HBHP exhibited markedly higher removal efficiencies for DRN compared to Ho2YSbO7, Bi2MoO6, or N-doped TiO2 photocatalyst, with removal efficiencies 1.13 times, 1.21 times, or 2.95 times higher, respectively. Similarly, the HBHP demonstrated significantly higher removal efficiencies for TOC compared to Ho2YSbO7, Bi2MoO6, or N-doped TiO2 photocatalyst, with removal efficiencies 1.17 times, 1.25 times, or 3.39 times higher, respectively. Furthermore, the HBHP demonstrated excellent stability and reusability. The mechanisms which could enhance the photocatalytic activity remarkably and the involvement of the major active species were comprehensively discussed, with superoxide radicals identified as the primary active species, followed by hydroxyl radicals and holes. The results of this study contribute to the advancement of efficient heterostructural materials and offer valuable insights into the development of sustainable remediation strategies for addressing DRN contamination.


Subject(s)
Bismuth , Diuron , Light , Molybdenum , Photolysis , Bismuth/chemistry , Catalysis , Molybdenum/chemistry , Diuron/chemistry , Water Pollutants, Chemical/chemistry
15.
Int J Biol Macromol ; 267(Pt 2): 131538, 2024 May.
Article in English | MEDLINE | ID: mdl-38621572

ABSTRACT

Lignin is continuously investigated by various techniques for valorization due to its high content of oxygen-containing functional groups. Catalytic systems employing hydrolysis­hydrogenolysis, leveraging the synergistic effect of redox metal sites and acid sites, exhibit efficient degradation of lignin. The predominance of either hydrolysis or hydrogenolysis reactions hinges upon the relative activity of acid and metal sites, as well as the intensity of the reductive atmosphere. In this study, the Pd-MoOx/TiO2 catalyst was found to primarily catalyze hydrolysis in the lignin depolymerization process, attributed to the abundance of moderate acidic sites on Pd and the redox-assisted catalysis of MoOx under inert conditions. After subjecting the reaction to 240 °C for 30 h, a yield of 48.22 wt% of total phenolic monomers, with 5.90 wt% consisting of diphenols, was achieved. Investigation into the conversion of 4-propylguaiacol (4-PG), a major depolymerized monomer of corncob lignin, revealed the production of ketone intermediates, a phenomenon closely linked to the unique properties of MoOx. Dehydrogenation of the propyl is a key step in initiating the reaction, and 4-PG could be almost completely transformed, accompanied by an over 97 % of 4-propylcatechol selectivity. This distinctive system lays a new theoretical groundwork for the eco-friendly valorization of lignin.


Subject(s)
Lignin , Palladium , Titanium , Lignin/chemistry , Hydrolysis , Catalysis , Titanium/chemistry , Palladium/chemistry , Hydrogen/chemistry , Molybdenum/chemistry , Oxidation-Reduction , Oxides/chemistry
17.
ACS Appl Mater Interfaces ; 16(17): 21427-21437, 2024 May 01.
Article in English | MEDLINE | ID: mdl-38634539

ABSTRACT

In the pursuit of personalized medicine, the development of efficient, cost-effective, and reliable DNA sequencing technology is crucial. Nanotechnology, particularly the exploration of two-dimensional materials, has opened different avenues for DNA nucleobase detection, owing to their impressive surface-to-volume ratio. This study employs density functional theory with van der Waals corrections to methodically scrutinize the adsorption behavior and electronic band structure properties of a DNA system composed of eight hachimoji nucleotide letters adsorbed on both MoS2 and MoSSe monolayers. Through a comprehensive conformational search, we pinpoint the most favorable adsorption sites, quantifying their adsorption energies and charge transfer properties. The analysis of electronic band structure unveils the emergence of flat bands in close proximity to the Fermi level post-adsorption, a departure from the pristine MoS2 and MoSSe monolayers. Furthermore, leveraging the nonequilibrium Green's function approach, we compute the current-voltage characteristics, providing valuable insights into the electronic transport properties of the system. All hachimoji bases exhibit physisorption with a horizontal orientation on both monolayers. Notably, base G demonstrates high sensitivity on both substrates. The obtained current-voltage (I-V) characteristics, both without and with base adsorption on MoS2 and the Se side of MoSSe, affirm excellent sensing performance. This research significantly advances our understanding of potential DNA sensing platforms and their electronic characteristics, thereby propelling the endeavor for personalized medicine through enhanced DNA sequencing technologies.


Subject(s)
DNA , Disulfides , Molybdenum , Molybdenum/chemistry , Disulfides/chemistry , DNA/chemistry , Adsorption , Density Functional Theory
18.
J Colloid Interface Sci ; 667: 450-459, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38643742

ABSTRACT

Single-atom catalysts (SACs) have attracted extensive attention in the field of catalysis due to their excellent catalytic ability and enhanced atomic utilization, but the multi-mode single-atom nanozymes for biosensors remain a challenging issue. In this work, iron-doped carbon dots (Fe CDs) were loaded onto the edges and pores of Mo SACs with nanoflower morphology; accordingly, a composite material Fe CDs/Mo SACs was prepared successfully, which improves the catalytic performance and develops a fluorescence mode without changing the original morphology. The steady-state kinetic data indicates that the material prepared have better affinity for substrates and faster reaction rates under optimized conditions. The specific kinetic parameters Km and Vmax were calculated as 0.39 mM and 7.502×10-7 M·s-1 respectively. The excellent peroxidase-like activity of Fe CDs/Mo SACs allows H2O2 to decompose into •OH, which in turn oxidizes colorless o-phenylenediamine (OPD) to yellow 2,3-diaminophenazine (DAP). At the same time, the fluorescence signal of Fe CDs/Mo SACs quenches obviously by DAP at 460 nm through internal filtration effect (IFE), while the characteristic fluorescence response of DAP gradually increases at 590 nm. Based on this sensing mechanism, a sensitive and accurate dual-mode (colorimetric and ratiometric fluorescent) sensor was constructed to detect H2O2 and uric acid, and the rate of recovery and linearity were acceptable for the detection of UA in human serum and urine samples. This method provides a new strategy for rapid and sensitive detection of UA, and also broadens the development of SACs in the field of biosensors.


Subject(s)
Carbon , Hydrogen Peroxide , Iron , Molybdenum , Quantum Dots , Uric Acid , Uric Acid/analysis , Uric Acid/urine , Uric Acid/blood , Uric Acid/chemistry , Molybdenum/chemistry , Hydrogen Peroxide/analysis , Hydrogen Peroxide/chemistry , Carbon/chemistry , Iron/chemistry , Quantum Dots/chemistry , Catalysis , Humans , Biosensing Techniques , Limit of Detection , Particle Size , Nanostructures/chemistry , Surface Properties , Phenylenediamines/chemistry
19.
J Environ Manage ; 358: 120827, 2024 May.
Article in English | MEDLINE | ID: mdl-38608575

ABSTRACT

The environmental safety of nanoscale molybdenum disulfide (MoS2) has attracted considerable attention, but its influence on the horizontal migration of antibiotic resistance genes and the ecological risks entailed have not been reported. This study addressed the influence of exposure to MoS2 at different concentrations up to 100 mg/L on the conjugative transfer of antibiotic resistance genes carried by RP4 plasmids with two strains of Escherichia coli. As a result, MoS2 facilitated RP4 plasmid-mediated conjugative transfer in a dose-dependent manner. The conjugation of RP4 plasmids was enhanced as much as 7-fold. The promoting effect is mainly attributable to increased membrane permeability, oxidative stress induced by reactive oxygen species, changes in extracellular polymer secretion and differential expression of the genes involved in horizontal gene transfer. The data highlight the distinct dose dependence of the conjugative transfer of antibiotic resistance genes and the need to improve awareness of the ecological and health risks of nanoscale transition metal dichalcogenides.


Subject(s)
Disulfides , Drug Resistance, Microbial , Escherichia coli , Molybdenum , Plasmids , Molybdenum/chemistry , Plasmids/genetics , Disulfides/chemistry , Escherichia coli/genetics , Escherichia coli/drug effects , Drug Resistance, Microbial/genetics , Conjugation, Genetic , Anti-Bacterial Agents/pharmacology , Gene Transfer, Horizontal
20.
J Food Sci ; 89(5): 2747-2760, 2024 May.
Article in English | MEDLINE | ID: mdl-38563096

ABSTRACT

In this study, a new electrochemical sensor based on molybdenum disulfide (MoS2) nanoflowers/glassy carbon electrode (GCE was created for the sensitive detection of gluten. The prepared nanocatalysts were characterized using scanning electron microscopy with energy dispersive spectroscopy, x-ray diffraction, and x-ray photoelectron spectroscopy. The effects of the prepared nanocatalysts, pH value, and dropping amounts on the results were examined in detail. The electrochemical performance of the developed sensor (MoS2 nanoflowers/GCE) was then evaluated using differential pulse voltammetry, and the sensor was found to have significant electrochemical activity against gluten. A substantial linear connection was observed in the range of 0.5-100 ppm of gluten concentration under optimum experimental circumstances, and the detection limit between peak current and gluten concentration was determined as 1.16 ppm. The findings showed that the MoS2 nanoflowers/GCE gluten sensor has exceptional selectivity and stability. Finally, the generated electrochemical sensor was effectively utilized for gluten detection in commercial gluten-containing materials with a detection limit of 0.1652 ppm. Thus, the developed MoS2 nanoflowers/GCE sensor offers a potential method for the detection of other molecules and is a promising candidate for gluten detection in commercial samples.


Subject(s)
Disulfides , Electrochemical Techniques , Enzyme-Linked Immunosorbent Assay , Glutens , Limit of Detection , Molybdenum , Molybdenum/chemistry , Disulfides/chemistry , Glutens/analysis , Electrochemical Techniques/methods , Electrochemical Techniques/instrumentation , Enzyme-Linked Immunosorbent Assay/methods , Electrodes , Nanostructures/chemistry , Food Contamination/analysis , Photoelectron Spectroscopy , X-Ray Diffraction
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