Bimetallic Ag/Cu incorporated into chemically exfoliated MoS2 nanosheets to enhance its antibacterial potential: in silico molecular docking studies

Hydrothermal Synthesis of Fe-Doped Cadmium Oxide Showed Bactericidal Behavior and Highly Efficient Visible Light Photocatalysis

Cationic dyes present in industrial effluents significantly reduce the effectiveness of remediation operations. Considering the terrible impact of these pollutants on environment and biodiversity, investigating strategies to remove potentially harmful compounds from water is becoming an increasingly intriguing issue. In this work, we employed a simple hydrothermal technique to synthesize Fe-doped CdO (2, 4, and 6 wt %) nanostructures and assessed their efficacy in degrading methylene blue (MB) dye and inhibiting the growth of Staphylococcus aureus and Escherichia coli, respectively. Structural, morphological, and optical characterization of produced nanomaterials was also performed using X-ray diffraction, TEM, and UV absorption spectra. The photocatalytic decomposition of MB was significantly enhanced (58.8%) by using Fe (6 wt %)-doped CdO catalysts for 80 min under irradiation. In addition, 2.05-5.05 mm inhibitory zones were seen against Gram-positive bacteria (S. aureus), whereas the range for Gram-negative bacteria (E. coli) was 1.65-2.75 mm. These nanostructures were shown to be very effective inhibitors of beta-lactamase, d-alanine-d-alanine ligase B, and fatty acid synthase inhibitor by in silico molecular docking investigations.

Facile Synthesis of Vanadium Oxide/Carbon Spheres-Doped Nickel Oxide Functioned as a Nanocatalyst and Bactericidal Behavior with Molecular Docking Analysis

Vanadium oxide (V₂O₅) and carbon spheres (Cs)-doped NiO₂ nanostructures (NSs) were prepared using the co-precipitation approach. Several spectroscopic and microscopic techniques, including X-ray diffraction (XRD), UV-vis, FTIR, TEM, and HR-TEM investigations, were used to describe the as-synthesized NSs. The XRD pattern exhibited the hexagonal structure, and the crystallite size of pristine and doped NSs was calculated as 29.3, 32.8, 25.79, and 45.19 nm, respectively. The control sample (NiO₂) showed maximum absorption at 330 nm, and upon doping, a redshift was observed, leading to decreased band gap energy from 3.75 to 3.59 eV. TEM of NiO₂ shows agglomerated nonuniform nanorods exhibited with various nanoparticles without a specific orientation; a higher agglomeration was observed upon doping. The (4 wt %) V₂O₅/Cs-doped NiO₂ NSs served as superior catalysts with a 94.21% MB reduction in acidic media. The significant antibacterial efficacy was estimated against Escherichia coli by measuring the zone of inhibition (3.75 mm). Besides their bactericidal analysis, V₂O₅/Cs-doped NiO₂ was shown to have a binding score of 6.37 for dihydrofolate reductase and a binding score of 4.31 for dihydropteroate synthase in an in silico docking study of E. coli.

In-vitro synergistic microbicidal and catalytic evaluation of polyvinylpyrrolidone/chitosan doped tungsten trioxide nanoplates with evidential in-silico analysis

In this research, hydrothermally synthesized tungsten trioxide (WO₃) nanocomposites doped polyvinylpyrrolidone (PVP) and chitosan (CS) were studied. Various concentrations (3, 6, and 9 wt%) of PVP were doped into a fixed amount of binary system (CS-WO₃) nanocomposites. PVP/CS polymers showed attractive attention because of their different structure, functionality, and architecture control as dopant to WO₃. The PVP/CS encapsulates the WO₃ (ternary composite), which controls crystallite size (band gap reduction), rapidly overcomes the recombination electron-hole pairs issues, and generates the active sites, resulting in improved catalytic and antimicrobial activity. The synthesized nanocomposites revealed significant catalytic efficiency and methylene blue (MB) dye depletion of 99.9 % in the presence of reducing agent (NaBH₄) in neutral and acidic media. Antimicrobial effectiveness of produced nanostructures towards Escherichia coli (E. coli) pathogen at low and high concentrations were investigated by Vernier caliper in mm. Furthermore, to their microbicidal action, docking experiments of CS-doped WO₃ and PVP/CS-doped WO₃ nanostructures for DHFR and FabI of Escherichia coli suggested blockage of aforesaid enzymes as the plausible pathway.

Fabrication and characterization of the Fe3O4@SiO2-rGO nanocomposite: a catalyst for multi-component reactions

A novel nanocomposite is synthesized by covalently modifying reduced graphene oxide (rGO) with Fe₃O₄@SiO₂ nanoparticles. Fe₃O₄ was synthesized using a co-precipitation method, and SiO₂ was then coated onto the Fe₃O₄via a sol-gel method. Graphene oxide was synthesized using the Hummers' method. Furthermore, a hydrothermal method was applied to create the Fe₃O₄@SiO₂-GO composite, and a simple reduction was used to obtain three-dimensional (3D) Fe₃O₄@SiO₂-rGO core-shell spheres. XRD, FTIR, FE-SEM, VSM, BET, TGA, and Raman analyses were used to characterize the prepared nanocomposites. X-Ray diffraction (XRD) and Raman spectra reveal that the nanostructures consist of highly crystallized cubic Fe₃O₄, amorphous SiO₂, and rGO sheets stacked in a disordered fashion. Field emission scanning electron microscopy (FE-SEM) characterization indicates that the form of the Fe₃O₄@SiO₂ core-shell structures is spherical, with an average size of about 25 nm. Magnetic hysteresis loops reveal the super-paramagnetic behavior of the samples at room temperature. All of the results obtained confirm the synthesis of high-quality nanocomposites, which can be a good candidate for use as a catalyst in multi-component reactions.

Molybdenum-doped iron oxide nanostructures synthesized via a chemical co-precipitation route for efficient dye degradation and antimicrobial performance: in silico molecular docking studies

In this research, various concentrations of molybdenum (2, 4 and 6 wt%) doped Fe₃O₄ nanostructures (Mo-Fe₃O₄ NSs) were prepared via a co-precipitation technique. Various techniques were then used to investigate the optical, morphological and structural properties of the NSs in the presence of the dopant materials. X-ray diffraction (XRD) was used to investigate the crystalline nature of the prepared NSs and confirm the orthorhombic and tetragonal structure of Fe₃O₄, with a decrease in crystallinity and crystallite sizes of 36.11, 38.45, 25.74 and 24.38 nm with increasing concentration of Mo (2, 4 and 6%). Fourier-transform infrared (FTIR) spectroscopy analysis was carried out to examine the functional groups in the NSs. Structure, surface morphology and topography were examined via field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM), which confirmed the fabrication of nanoparticles and nanorods and a floccule-like morphology with a higher doping concentration and the interlayer d-spacing was calculated using high-resolution (HR)TEM, the results of which were a good match to the XRD data. The presence of Mo, Fe and O in a lattice of Mo (2, 4 and 6%) doped Fe₃O₄ was confirmed by energy dispersive X-ray spectroscopy (EDS) analysis. The energy band gap (E _g) was measured via the optical analysis of pure and doped samples, showing a decrease from 2.76 to 2.64 eV. The photoluminescence (PL) spectra exhibit a higher charge combination rate of electron-hole pairs with a higher concentration of doping. The NSs exhibited excellent catalytic activity (CA) in degrading methylene blue (MB) dye in a basic medium by around 86.25%. Additionally, the antimicrobial activity was tested against Escherichia coli (E. coli) bacteria. Pairs of electrons and holes are the fundamental basis for generating reactive oxygen species that kill bacteria. The significant inhibition zones were calculated against E. coli bacteria at around 3.45 mm compared to ciprofloxacin. In silico docking investigations of the Mo-Fe₃O₄ NSs for dihydropteroate synthase (DHPS, binding score: 6.16 kcal mol^-1), dihydrofolate reductase (DHFR, binding score: 6.01 kcal mol^-1), and β-ketoacyl-acyl carrier protein synthase III (FabH, binding score: 5.75 kcal mol^-1) of E. coli show the suppression of the aforementioned enzymes as a potential mechanism besides their microbicidal assay.

Photocatalytic and antibacterial activity of graphene oxide/cellulose-doped TiO2 quantum dots: in silico molecular docking studies

Graphene oxide (GO) and cellulose nanocrystal (CNC)-doped TiO₂ quantum dots (QDs) were effectively synthesized by employing the co-precipitation method for the degradation of dyes and antimicrobial applications. A series of characterizations, i.e., XRD, FTIR, UV-visible spectroscopy, EDS, FE-SEM, and HR-TEM, was used to characterize the prepared samples. A reduction in PL intensity was observed, while the band gap energy (E _g) decreased from 3.22 to 2.96 eV upon the incorporation of GO/CNC in TiO₂. In the Raman spectra, the D and G bands were detected, indicating the presence of graphene oxide in the composites. Upon doping, the crystallinity of TiO₂ increased. HR-TEM was employed to estimate the interlayer d-spacing of the nanocomposites, which matched well with the XRD data. The photocatalytic potential of the prepared samples was tested against methylene blue, methylene violet, and ciprofloxacin (MB:MV:CF) when exposed to visible light for a certain period. The antibacterial activity of GO/CNC/TiO₂ QDs against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) bacteria in vitro was tested to determine their potential for medicinal applications. The molecular docking investigations of CNC-TiO₂ and GO/CNC-doped TiO₂ against DNA gyrase and FabI from E. coli and S. aureus were found to be consistent with the results of the in vitro bactericidal activity test. We believe that the prepared nanocomposites will be highly efficient for wastewater treatment and antimicrobial activities.

Recent Progress in Phase Regulation, Functionalization, and Biosensing Applications of Polyphase MoS2

The disulfide compounds of molybdenum (MoS₂ ) are layered van der Waals materials that exhibit a rich array of polymorphic structures. MoS₂ can be roughly divided into semiconductive phase and metallic phase according to the difference in electron filling state of the 4d orbital of Mo atom. The two phases show completely different properties, leading to their diverse applications in biosensors. But to some extent, they compensate for each other. This review first introduces the relationship between phase state and the chemical/physical structures and properties of MoS₂ . Furthermore, the synthetic methods are summarized and the preparation strategies for metastable phases are highlighted. In addition, examples of electronic and chemical property designs of MoS₂ by means of doping and surface modification are outlined. Finally, studies on biosensors based on MoS₂ in recent years are presented and classified, and the roles of MoS₂ with different phases are highlighted. This review offers references for the selection of materials to construct different types of biosensors based on MoS₂ , and provides inspiration for sensing performance enhancement.

MoS2 based nanomaterials: Advanced antibacterial agents for future

Bacterial infections are yet another serious threat to human health. Misuse or overuse of conventional antibiotics has led to the arrival of various super resistant bacteria along with many serious side effects to human body. In this exigent circumstance, the use of nanomaterial based antibacterial agents is one of the most appropriate solutions to fight against bacteria thereby causing an inhibition to bacterial proliferation. Recent studies show that, due to the large surface area, high biocompatibility, strong near-infrared (NIR) absorption and low cytotoxicity, molybdenum disulphide (MoS₂), an extraordinary member in the transition metal dichalcogenides (TMDs) is extensively explored in the obliteration of many drug resistant bacteria, photothermal therapy and drug delivery. MoS₂ based nanomaterials can effectively prevent bacterial growth through many mechanisms. Through this review, we have tried to provide an inclusive knowledge on the recent progress of antibacterial studies in MoS₂ based nanomaterials including MoS₂ nanosheets, nanoflowers, quantum dot (QD), hybrid nanocomposites and polymer nanocomposites. Moreover, toxicity of MoS₂ based nanomaterials is described at the end of the review.

Advances in Nanostructures for Antimicrobial Therapy

Microbial infections caused by a variety of drug-resistant microorganisms are more common, but there are fewer and fewer approved new antimicrobial chemotherapeutics for systemic administration capable of acting against these resistant infectious pathogens. Formulation innovations of existing drugs are gaining prominence, while the application of nanotechnologies is a useful alternative for improving/increasing the effect of existing antimicrobial drugs. Nanomaterials represent one of the possible strategies to address this unfortunate situation. This review aims to summarize the most current results of nanoformulations of antibiotics and antibacterial active nanomaterials. Nanoformulations of antimicrobial peptides, synergistic combinations of antimicrobial-active agents with nitric oxide donors or combinations of small organic molecules or polymers with metals, metal oxides or metalloids are discussed as well. The mechanisms of actions of selected nanoformulations, including systems with magnetic, photothermal or photodynamic effects, are briefly described.

Biogenic Synthesis, Characterization and Antibacterial Potential Evaluation of Copper Oxide Nanoparticles Against Escherichia coli

The development of resistance against antibiotics used to treat bacterial infections along with the prevalence of medication residues presents significant public health problems globally. Antibiotic-resistant germs result in infections that are difficult or impossible to treat. Decreasing antibiotic effectiveness calls for rapid development of alternative antimicrobials. In this respect, nanoparticles (NPs) of copper oxide (CuO) manifest a latent and flexible inorganic nanostructure with noteworthy antimicrobial impact. Green synthesis of CuO NPs was performed in the current study, which was then doped with varying amounts of ginger (Zingiber officinale, ZO) and garlic (Allium sativum, AS) extracts. In low and high doses, the synthesized compound was used to measure the antimicrobial effectiveness against pathogenic Escherichia coli. The present research successfully demonstrated a renewable, eco-friendly synthesis technique with natural materials that is equally applicable to other green metal oxide NPs.

Novel prism shaped C3N4-doped Fe@Co3O4 nanocomposites and their dye degradation and bactericidal potential with molecular docking study

Novel prism shaped C₃N₄-doped Fe@Co₃O₄ nanocomposites were fabricated via a co-precipitation route for effective removal of organic pollutants from water and for bactericidal applications. Doping of C₃N₄ in the heterojunction significantly enhanced the photocatalytic and sonocatalytic activity against methylene blue ciprofloxacin (MBCF) dye. The main purpose of doping Fe atoms in the cobalt lattice was to generate crystal and surface defects. Moreover, the optimum doping amount of C₃N₄ for maximum degradation performance was evaluated. A detailed examination of the prepared nanocomposites was carried out systematically using various characterization tools for better understanding. HR-TEM images revealed the formation of novel prism shaped structures that exhibited outstanding degradation of the organic dye in water. Significant bactericidal potential was also observed for the synthesized nanocomposites against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) bacteria. In silico, molecular docking studies against β-lactamase, DHFR and FabI enzymes served to elucidate the mechanism governing the bactericidal activity of the as-synthesized nanoparticles (NPs). Furthermore, a scavenging study by DPPH (2,2-diphenyl-1-picrylhydrazyl) assay and COD (chemical oxygen demand) analysis was performed in order to evaluate active species and the anti-oxidant potential of prepared composites.

This study provides new insights into the use of cobalt-based heterojunction photocatalysts for dye degradation and antibacterial applications (a) synthesis mechanism of C₃N₄ (b) schematic of synthesis route adopted for fabrication of nanocomposites.

Development of Multi-concentration Cu:Ag Bimetallic Nanoparticles as a Promising Bactericidal for Antibiotic-Resistant Bacteria as Evaluated with Molecular Docking Study

The present study is concerned with evaluating the influence of various concentrations of Ag within Cu:Ag bimetallic nanoparticles developed for use as a promising anti-bacterial agent against antibiotic-resistant bacteria. Here, Cu:Ag bimetallic nanoparticles with various concentration ratios (2.5, 5.0, 7.5, and 10 wt%) of Ag in fixed amount of Cu labeled as 1:0.025, 1:0.050, 1:0.075, and 1:0.1 were synthesized using co-precipitation method with ammonium hydroxide and deionized water as solvent, polyvinyl pyrrolidone as a capping agent, and sodium borohydride and ascorbic acid as reducing agents. These formulated products were characterized through a variety of techniques. XRD confirmed phase purity and detected the presence of distinct fcc structures belonging to Cu and Ag phases. FTIR spectroscopy confirmed the presence of vibrational modes corresponding to various functional groups and recorded characteristic peak emanating from the bimetallic. UV-visible spectroscopy revealed reduction in band gap with increasing Ag content. SEM and HR-TEM micrographs revealed spherical morphology of Ag-doped Cu bimetallic with small and large scale agglomerations. The samples exhibited varying dimensions and interlayer spacing. Bactericidal action of synthesized Cu:Ag bimetallic NPs depicted statistically significant (P < 0.05) inhibition zones recorded for various concentrations of Ag dopant against Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), and Acinetobacter baumannii (A. baumannii) ranging from (0.85-2.8 mm), (0.55-1.95 mm) and (0.65-1.85 mm), respectively. Broadly, Cu:Ag bimetallic NPs were found to be more potent against gram-positive compared with gram-negative. Molecular docking study of Ag-Cu bimetallic NPs was performed against β-lactamase which is a key enzyme of cell wall biosynthetic pathway from both S. aureus (Binding score: - 4.981 kcal/mol) and A. bauminnii (Binding score: - 4.013 kcal/mol). Similarly, binding interaction analysis against FabI belonging to fatty acid biosynthetic pathway from A. bauminnii (Binding score: - 3.385 kcal/mol) and S. aureus (Binding score: - 3.012 kcal/mol) along with FabH from E. coli (Binding score: - 4.372 kcal/mol) was undertaken. These theoretical computations indicate Cu-Ag bimetallic NPs as possible inhibitor of selected enzymes. It is suggested that exploring in vitro inhibition potential of these materials may open new avenues for antibiotic discovery.

Impact of Bi Doping into Boron Nitride Nanosheets on Electronic and Optical Properties Using Theoretical Calculations and Experiments

In the present work, boron nitride (BN) nanosheets were prepared through bulk BN liquid phase exfoliation while various wt. ratios (2.5, 5, 7.5 and 10) of bismuth (Bi) were incorporated as dopant using hydrothermal technique. Our findings exhibit that the optical investigation showed absorption spectra in near UV region. Density functional theory calculations indicate that Bi doping has led to various modifications in the electronic structures of BN nanosheet by inducing new localized gap states around the Fermi level. It was found that bandgap energy decrease with the increase of Bi dopant concentrations. Therefore, in analysis of the calculated absorption spectra, a redshift has been observed in the absorption edges, which is consistent with the experimental observation. Additionally, host and Bi-doped BN nanosheets were assessed for their catalytic and antibacterial potential. Catalytic activity of doped free and doped BN nanosheets was evaluated by assessing their performance in dye reduction/degradation process. Bactericidal activity of Bi-doped BN nanosheets resulted in enhanced efficiency measured at 0-33.8% and 43.4-60% against S. aureus and 0-38.8% and 50.5-85.8% against E. coli, respectively. Furthermore, In silico molecular docking predictions were in good agreement with in-vitro bactericidal activity. Bi-doped BN nanosheets showed good binding score against DHFR of E. coli (- 11.971 kcal/mol) and S. aureus (- 8.526 kcal/mol) while binding score for DNA gyrase from E. coli (- 6.782 kcal/mol) and S. aureus (- 7.819 kcal/mol) suggested these selected enzymes as possible target.

Doping of Mg on ZnO Nanorods Demonstrated Improved Photocatalytic Degradation and Antimicrobial Potential with Molecular Docking Analysis

Various concentrations of Mg-doped ZnO nanorods (NRs) were prepared using co-precipitation technique. The objective of this study was to improve the photocatalytic properties of ZnO. The effect of Mg doping on the structure, phase constitution, functional groups presence, optical properties, elemental composition, surface morphology and microstructure of ZnO was evaluated with XRD, FTIR, UV-Vis spectrophotometer, EDS, and HR-TEM, respectively. Optical absorption spectra obtained from the prepared samples showed evidence of blueshift upon doping. XRD results revealed hexagonal wurtzite phase of nanocomposite with a gradual decrease in crystallite size with Mg addition. PL spectroscopy showed trapping efficiency and migration of charge carriers with electron-hole recombination behavior, while HR-TEM estimated interlayer d-spacing. The presence of chemical bonding, vibration modes and functional groups at the interface of ZnO was revealed by FTIR and Raman spectra. In this study, photocatalytic, sonocatalytic and sonophotocatalytic performance of prepared NRs was systematically investigated by degrading a mixture of methylene blue and ciprofloxacin (MBCF). Experimental results suggested that improved degradation performance was shown by Mg-doped ZnO NRs. We believe that the product synthesized in this study will prove to be a beneficial and promising photocatalyst for wastewater treatment. Conclusively, Mg-doped ZnO exhibited substantial (p < 0.05) efficacy against gram-negative (G-ve) as compared to gram-positive (G+ve) bacteria. In silico molecular docking studies of Mg-doped ZnO NRs against DHFR (binding score: - 7.518 kcal/mol), DHPS (binding score: - 6.973 kcal/mol) and FabH (- 6.548 kcal/mol) of E. coli predicted inhibition of given enzymes as possible mechanism behind their bactericidal activity.

Silver decorated 2D nanosheets of GO and MoS2serve as nanocatalyst for water treatment and antimicrobial applications as ascertained with molecular docking evaluation

In this work, synthesis of graphene oxide (GO) and reduced graphene oxide (rGO) was realized through a modified Hummers route. Different concentrations (5 and 10 wt%) of Ag were doped in MoS₂and rGO using a hydrothermal technique. Synthesized Ag-MoS₂and Ag-rGO were evaluated through XRD that confirmed the hexagonal structure of MoS₂along with the transformation of GO to Ag-rGO as indicated by a shift in XRD peaks while Mo-O bonding and S=O functional groups were confirmed with FTIR. Morphological information of GO and formation of MoS₂nanopetals as well as interlayer spacing were verified through FESEM and HRTEM respectively. Raman analysis was employed to probe any evidence regarding defect densities of GO. Optical properties of GO, MoS₂, Ag-rGO, and Ag-MoS₂were visualized through UV-vis and PL spectroscopy. Prepared products were employed as nanocatalysts to purify industrial wastewater. Experimental results revealed that Ag-rGO and Ag-MoS₂showed 99% and 80% response in photocatalytic activity. Besides, the nanocatalyst (Ag-MoS₂and Ag-rGO) exhibited 6.05 mm inhibition zones againstS. aureusgram positive (G+) and 3.05 mm forE. coligram negative (G-) in antibacterial activity. To rationalize biocidal mechanism of Ag-doped MoS₂NPs and Ag-rGO,in silicomolecular docking study was employed for two enzymes i.e.β-lactamase and D-alanine-D-alanine ligase B (ddlB) from cell wall biosynthetic pathway and enoyl-[acylcarrier-protein] reductase (FabI) from fatty acid biosynthetic pathway belonging toS. aureus. The present study provides evidence for the development of cost-effective, environment friendly and viable candidate for photocatalytic and antimicrobial applications.

Liquid-phase exfoliated MoS2 nanosheets doped with p-type transition metals: a comparative analysis of photocatalytic and antimicrobial potential combined with density functional theory

MoS2 nanosheets were developed by undertaking the liquid-phase exfoliation of bulk counterparts. In order to enhance its photocatalytic properties, the host material was doped with p-type transition metals (i.e., Ag, Co, Bi, and Zr). The hydrothermal technique was used to produce samples doped with 7.5 wt% transition metals (TM). X-ray diffraction detected the existence of 2H-phase by mirroring its reflection at 2θ ∼ 14°, while the peak distribution revealed the degree of exfoliation in samples. Low PL intensities indicated a lower recombination of electron-hole pairs, as corroborated by a high degree of photocatalytic action. Raman analysis was undertaken to identify molecular vibrations. The A1g mode in Raman spectra consistently showed a blueshift in all samples and the E12g mode was only slightly affected, which is evidence of the p-type doping in the MoS2 nanosheets. In the XPS spectrum, two characteristic peaks of Mo 3d appeared at 229.87 and 233.03 eV assigned to Mo-3d5/2 and Mo-3d3/2, respectively. Furthermore, a microstructural examination with HR-TEM and FESEM divulged a thin-layered structure of MoS2 consisting of flat, gently curved or twisted nanosheets. Diverse morphologies were observed with a non-uniform distribution of the dopant. Photocatalytic action of the TM-doped products effectively degraded methylene blue (MB) concentrations of up to 94 percent (for Ag-MoS2). The synergistic effect of doped MoS2 nanosheets against S. aureus in comparison to E. coli bacteria was also evaluated. The efficacy % age improved from (0-31.7%) and (23.5-55.2%) against E. coli, and (0-34.2%) and (8.3-69.23%) against S. aureus. Moreover, results from first principles calculations indicate that substitutional doping of TM atoms is indeed advantageous. Theoretical calculations confirmed that doping with Ag, Co, Bi, and Zr leads to a decrease in the band gap to a certain degree, in which the conduction band edge shifts toward lower energy, while the valence band shifts closer to the high energy end. It can be concluded that Ag, Co, and Bi impurities can lead to beneficial p-type doping in MoS2 monolayered structures. With regards to doping with Zr, the acceptor levels are formed above the edge of the valence band, revealing an introduction of the p-type character.

Understanding the Structural-Dependent Photocatalytic Antibacterial Activity: a Case Study of Ag Modified BiVO4

In this work, Ag/BiVO₄ heterostructural photocatalysts were developed in order to reveal exceptional structural-dependent photoinduced charge migration kinetics as well as the underlying photocatalytic antibacterial dynamic process. The structure-dependent interface of BiVO₄ and Ag nanoparticles was successfully constructed to improve the photoinduced interface charge transfer efficiency and interface correlation. DFT calculation indicated that a net charge of about 0.33 e between Ag and tz-BiVO₄ was achieved by extraordinary interface charge transfer, being far larger than that between Ag and ms-BiVO₄. Larger net charge has consequences on mobility of charge carriers of tz-BiVO₄ that can raise the migration and separation of charge carriers for Ag/tz-BiVO₄ heterojunction. Fine interfacial contact between Ag and tz-BiVO₄ led to the optimized photocatalytic performance toward E. coli inactivation, being predominately higher than that of tz-BiVO₄, ms-BiVO₄, and Ag/ms-BiVO₄ catalysts. Besides photocatalytic activity, the thermocatalytic inactivation activity of Ag/tz-BiVO₄ also exhibited a factor of about 7.2 and 3.1 times higher than that of tz-BiVO₄ and Ag/ms-BiVO₄. Trapping and EPR measurements suggested that the structural-dependent photocatalytic activity of Ag/BiVO₄ mainly originated from the pronounced variation of the capability to produce H₂O₂ active species, where the capability of generating H₂O₂ over Ag/tz-BiVO₄ is highly accelerated. Moreover, it cannot be ignored that this study provides an ideal candidate for many aspects, such as environmental and water pollution caused by pathogenic microorganisms and disinfection of medical materials, food packaging, household materials, and public places, etc.

Comparative Study of Selenides and Tellurides of Transition Metals (Nb and Ta) with Respect to its Catalytic, Antimicrobial, and Molecular Docking Performance

The present research is a comparative study that reports an economical and accessible method to synthesize niobium (Nb) and Tantalum (Ta) selenides and tellurides with useful application in the removal of pollutants in textile, paper, and dyeing industries as well as in medical field. In this study, solid-state process was used to generate nanocomposites and various characterization techniques were employed to compare two groups of materials under investigation. Structure, morphology, elemental constitution, and functional groups of synthesized materials were analyzed with XRD, FESEM coupled with EDS, FTIR, and Raman spectroscopy, respectively. HR-TEM images displayed nanoscale particles with tetragonal and monoclinic crystal structures. The optical properties were evaluated in terms of cut-off wavelength and optical band gap using UV-visible spectroscopy. A comparative behavior of both groups of compounds was assessed with regards to their catalytic and microcidal properties. Extracted nanocomposites when used as catalysts, though isomorphs of each other, showed markedly different behavior in catalytic degradation of MB dye in the presence of NaBH₄ that was employed as a reducing agent. This peculiar deviation might be attributed to slight structural differences between them. Escherichia coli and Staphylococcus aureus (G -ve and + ve bacteria, respectively) were designated as model strains for in vitro antibacterial tests of both clusters by employing disk diffusion method. Superior antibacterial efficacy was observed for telluride system (significant inhibition zones of 26-35 mm) compared with selenide system (diameter of inhibition zone ranged from 0.8 mm to 1.9 mm). In addition, molecular docking study was undertaken to ascertain the binding interaction pattern between NPs and active sites in targeted cell protein. The findings were in agreement with antimicrobial test results suggesting NbTe₄ to be the best inhibitor against FabH and FabI enzymes.

Dye degradation performance, bactericidal behavior and molecular docking analysis of Cu-doped TiO2 nanoparticles

Copper-doped TiO2 was prepared with a sol-gel chemical method. Various concentrations (3, 6, and 9 wt%) of Cu dopant were employed. Several techniques were implemented to assess the structural, optical, morphological and chemical properties of the synthesized samples. Evaluation of elemental composition using SEM-EDS and XRF techniques showed the presence of dopant element in the prepared samples. XRD analysis confirmed the presence of anatase (TiO2) phase with interstitial doping. Incorporation of dopant was observed to enhance the crystallinity and increase the crystallite size of the synthesized products. SAED profiles revealed a high degree of crystallinity in the prepared specimens, which was also evident in the XRD spectra. Optical properties studied using UV-vis spectroscopy depicted a shift of the maximum absorption to the visible region (redshift) that signified a reduction in the band gap energy of Cu-doped TiO2 samples. Examination of morphological features with scanning and high-resolution transmission electron microscopes revealed the formation of spherical nanoparticles with a tendency to agglomerate with increasing dopant concentration. Molecular vibrations and the formation of Ti-O-Ti bonds were revealed through FTIR spectra. PL spectroscopy recorded the trapping efficiency and migration of charge carriers, which exhibited electron-hole recombination behavior. Doped nanostructures showed enhanced bactericidal performance and synergism against S. aureus and E. coli. In summary, Cu-doped TiO2 nanostructures were observed to impede bacteria effectively, which is deemed beneficial in overcoming ailments caused by pathogens such as microbial etiologies. Furthermore, molecular docking analysis was conducted to study the interaction of Cu-doped TiO2 nanoparticles with multiple proteins namely β-lactamase (binding score: -4.91 kcal mol-1), ddlB (binding score: -5.67 kcal mol-1) and FabI (binding score: -6.13 kcal mol-1) as possible targets with active site residues. Dye degradation/reduction of control and Cu-doped samples were studied through absorption spectroscopy. The obtained outcomes of the performed experiment indicated that the photocatalytic activity of Cu-TiO2 enhanced with increasing dopant concentration, which is thought to be due to a decreased rate of electron-hole pair recombination. Consequently, it is suggested that Cu-TiO2 can be exploited as an effective candidate for antibacterial and dye degradation applications.

Bactericidal behavior of chemically exfoliated boron nitride nanosheets doped with zirconium

In this work, boron nitride nanosheets (BNNS) were produced through chemical exfoliation of bulk boron nitride (BN). Furthermore, hydrothermal technique was used to incorporate various concentrations (2.5, 5, 7.5, and 10 wt%) of zirconium (Zr) as a dopant. The prepared undoped and doped BN samples were evaluated for its antimicrobial activity against E. coli and S. aureus. Structural analysis was undertaken using x-ray diffraction which identified the presence of hexagonal BN. FTIR and Raman spectroscopy were utilized to outline IR fingerprint and electronic properties of the synthesized material. Morphological information was obtained through micrographs extracted using field emission scanning electron spectroscope (FESEM) and high resolution transmission electron microscope (HRTEM), while d-spacing was also calculated through HRTEM analysis. Optical properties and emission spectra were examined by applying UV–vis and photoluminescence spectroscope (PL); whereas, band gap analysis was carried out via Tauc plot. Zr-doped BN nanosheets at increasing concentrations (0.5, 1.0 mg/50 μl) revealed enhanced antibacterial activity against E. coli compared to S. aureus (p < 0.05).

Effect of iron doped titanium oxide encapsulated in alginate on photocatalytic activity for the removal of dye pollutants

Iron oxide/titania oxide are encapsulated in alginate biopolymer. These bio-nanocomposites are suitable for the photodegradation of dissimilar organic pollutants under UV irradiation as well as visible light.

Enhanced UV stability of N-halamine-immobilized Fe3O4@SiO2@TiO2 nanoparticles: synthesis, characteristics and antibacterial property

Recycling of N-halamine-modified Fe₃O₄@SiO₂@TiO₂ antibacterial materials with UV stability.

Photocatalytic and bactericidal properties and molecular docking analysis of TiO2 nanoparticles conjugated with Zr for environmental remediation

Despite implementing several methodologies including a combination of physical, chemical and biological techniques, aquatic and microbial pollution remains a challenge to this day. Recently, nanomaterials have attracted considerable attention due to their extraordinary prospective for utilization toward environmental remediation. Among several probable candidates, TiO₂ stands out due to its potential for use in multifaceted applications. One way to improve the catalytic and antimicrobial potential of TiO₂ is to dope it with certain elements. In this study, Zr-doped TiO₂ was synthesized through a sol–gel chemical method using various dopant concentrations (2, 4, 6, and 8 wt%). Surface morphological, microstructural and elemental analysis was carried out using FESEM and HR-TEM along with EDS to confirm the formation of Zr–TiO₂. XRD spectra showed a linear shift of the (101) anatase peak to lower diffraction angles (from 25.4° to 25.08°) with increasing Zr⁴⁺ concentration. Functional groups were examined via FTIR, an ample absorption band appearing between 400 and 700 cm⁻¹ in the acquired spectrum was attributed to the vibration modes of the Ti–O–Ti linkage present within TiO₂ nanoparticles, which denotes the formation of TiO₂. Experimental results indicated that with increasing dopant concentrations, photocatalytic potential was enhanced significantly. In this respect, TiO₂ doped with 8 wt% Zr (sample 0.08 : 1) exhibited outstanding performance by realizing 98% elimination of synthetic MB in 100 minutes. This is thought to be due to a decreased rate of electron–hole pair recombination that transpires upon doping. Therefore, it is proposed that Zr-doped TiO₂ can be used as an effective photocatalyst material for various environmental and wastewater treatment applications. The good docking scores and binding confirmation of Zr-doped TiO₂ suggested doped nanoparticles as a potential inhibitor against selected targets of both E. coli and S. aureus. Hence, enzyme inhibition studies of Zr-doped TiO₂ NPs are suggested for further confirmation of these in silico predictions.

Despite implementing several methodologies including a combination of physical, chemical and biological techniques, aquatic and microbial pollution remains a challenge to this day.