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A new non-centrosymmetric Chlorobismuthate(III) hybrid material: Crystal structure, optical properties and antibacterial study
摘要： As part of our interest in organic-inorganic metallate complexes, we had prepared a novel non-centrosymmetric chlorobismuthate (III) compound with the chemical formula (C6H7NCl)3 [BiCl6]$H2O, by slow evaporation method at room temperature. It was characterized by single crystal X-ray diffraction (SCXRD), X-ray powder diffraction (PXRD), spectroscopic measurements, thermal study, Hirshfeld surface analysis, DFT investigation, and antimicrobial activity. A preliminary SCXRD structural analysis revealed that the compound crystallizes in the Orthorhombic system (P212121 space group) with the following unit cell parameters a ? 7.3432 (1) ?, b ? 13.8257 (2) ? and c ? 28.2140 (5) ? with Z ? 4 and V ? 2864.42 (8) ?3. The examination of the structure shows that its atomic arrangement can be described as inorganic [BiCl6]3- units isolated from each other by the organic cations and the co-crystallized water molecules. The cohesion between these entities is performed via the NeH/Cl, NeH/O, CeH/O, CeH/Cl, and OeH/Cl hydrogen bonding interactions between the 4-dichloroanilinium cations, the [BiCl6]3- anions and water molecules forming a 3D network. The Hirshfeld surface calculation was conducted to investigate: intermolecular interactions, associated 2D ?ngerprint plots, and enrichment ratio, indicating the relative contribution of these interactions in the crystal structure quantitatively. Thermal analysis reveals the decomposition of the compound at 180 (cid:2)C. The quantum mechanical calculations such as geometry optimization, vibrational frequencies, simulated UVeVisible spectrum, FMOs analysis were made together with the experimental studies. Furthermore, the new synthesized compound was screened for its antibacterial activity. Results revealed that it has the most effective activity against all the tested bacteria compared to the amine alone and to the BiOCl.
关键词： Hirshfeld surface analysis,Hybrid material,DFT calculations,Hexachlorobismuthate(III),X-ray diffraction,Antimicrobial activity
更新于2025-09-23 15:23:52
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Study of the photocatalysis and increase of antimicrobial properties of Fe3+and Pb2+ co-doped ZnO nanoparticles obtained by microwave-assisted hydrothermal method
摘要： The difficulty in treating organic effluents and increasing the resistance of microorganisms to conventional treatments promotes the development of new materials for these applications. In this work, it was obtained ZnO co-doped with Fe3+ and Pb2+ (ZnO:xFe:yPb, with x and y varying between 0, 1, 3 and 7 mol%) by microwave-assisted hydrothermal method with a reaction temperature of 140 °C for 30 min. The powders were characterized by X-ray diffraction (XRD), field-scanning electron microscopy (SEM), Brunauer-Emmett-Teller method (BET), ultraviolet diffuse reflectance spectroscopy (DRS-UV), X-ray fluorescence analysis (XRF) and Fourier transform infrared spectroscopy (FTIR). Photocatalytic properties were estimated by the degradation of the methylene blue dye when subjected to UV radiation. The antimicrobial properties were investigated by the formation of inhibition halos against E. coli and S. aureus bacteria. The XRD patterns show that there was no formation of secondary phases, obtaining only the ZnO phase, with hexagonal structure. Through the XRD, it can be seen that the intensity of the characteristic peaks is also reduced as the dopant concentration increases, indicating the appearance of defects in the crystalline lattice. SEM images show that an increase in the dopant concentration promotes a loss in the morphology of ZnO nanoparticles, accompanied by a reduction in their mean size. The co-doping reduces the photocatalytic activity of ZnO against the methylene blue dye, but increases the antimicrobial activity against E. coli and S. aureus bacteria.
关键词： Photocatalysis,ZnO,Antimicrobial activity,Co-doping
更新于2025-09-23 15:22:29
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Antimicrobial photodynamic therapy with phenothiazinium photosensitizers in non-vertebrate model Galleria mellonella infected with Fusarium keratoplasticum and Fusarium moniliforme
摘要： Fusarium keratoplasticum and Fusarium moniliforme are filamentous fungi common in the environment and cause mycosis in both animals and plants. Human infections include mycetoma, keratitis and onychomycosis, while deeper mycosis occurs in immunocompromised patients. Most of the Fusarium spp. are frequently resistant to treatment with currently used antifungals. The frequent occurrence of antifungal resistance has motivated the study of antimicrobial photodynamic therapy as an alternative treatment for fungal infections. Many studies have investigated the in vitro use of antimicrobial photodynamic therapy to kill fungi, but rarely in animal models of infection. Thus, here we employed the invertebrate wax moth Galleria mellonella to study the in vivo effects of antimicrobial photodynamic therapy with three different phenothiazinium photosensitizers, methylene blue, new methylene blue N and the pentacyclic S137 against infection with microconidia of Fusarium keratoplasticum and Fusarium moniliforme. The effect of antimicrobial photodynamic therapy using these photosensitizers and light-emitting diodes with an emission peak at 635 nm and an integrated irradiance from 570 to 670 nm of 9.8 mW cm?2 was investigated regarding the toxicity, fungal burden, larval survival and cellular immune response. The results from this model indicate that antimicrobial photodynamic therapy with methylene blue, new methylene blue N and S137 is efficient for the treatment of infection with F. keratoplasticum and F. moniliforme. The efficiency can be attributed to the fungal cell damage caused by antimicrobial photodynamic therapy which facilitates the action of the host immune response.
关键词： Antimicrobial photodynamic therapy,Fusarium keratoplasticum,Galleria mellonella,Mycosis,Fusarium moniliforme
更新于2025-09-23 15:22:29
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Machine-Washable Smart Textiles with Photothermal and Antibacterial Activities from Nanocomposite Fibers of Conjugated Polymer Nanoparticles and Polyacrylonitrile
摘要： Smart textiles based on conjugated polymers have been highlighted as promising fabrics that can intelligently respond to environmental stimuli based on the electrical properties of polymer semiconductors. However, there has been limited interest in the photothermal properties of conjugated polymers that can be applied to smart textiles. We prepared nanoparticles by assembling a conjugated polymer with a fatty acid via an emulsion process and nanocomposite fibers by distributing the conjugated polymer nanoparticles in a polyacrylonitrile matrix. We then fabricated the textiles using the fibers. The resulting fabrics based on nanocomposite fibers show a temperature increase to 50 °C in 10 min under white light irradiation because of efficient photothermal conversion by the conjugated polymer light harvester, while the temperature of a pristine polyacrylonitrile fabric increases to only 35 °C. In addition, excellent antimicrobial activity was confirmed by a 99.9% decrease in the populations of Staphylococcus aureus and Escherichia coli over 24 h because of the effect of the fatty acid in the nanocomposite films and fabrics. Furthermore, the fabric showed efficient durability after a laundry test, suggesting the usefulness of these smart textiles based on conjugated polymer nanoparticles for practical applications.
关键词： smart textiles,smart fabrics,antimicrobial fibers,photothermal conversion,nanocomposite fibers,conjugated polymer nanoparticles,polyacrylonitrile
更新于2025-09-23 15:22:29
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Photodynamic Antimicrobial Chemotherapy (PACT), using Toluidine blue (TBO) inhibits both growth and dimorphism in Paracoccidioides brasiliensis by a mechanism involving reactive Oxygen species (ROS) production
摘要： Background: The thermo-dimorphic fungus Paracoccidioides brasiliensis causes Paracoccidioidomycosis (PCM), an important public health problem in Latin American, with prevalence in Brazil [1-4]. One of the main problems of this mycosis, initially pulmonary, are the secondary mucosal lesions, which are debilitating, painful and, in some cases, generate mutilations [3,5-8]. The treatment is performed through the use of oral medicines anti-fungal and/or oral surgeries [3]. The Photodynamic Antimicrobial Chemotherapy (PACT) has been suggested as a promising alternative and/or complementary therapy against many pathogens [9-16] and has been little explored in the treatment of individuals with PCM [17-18]. Aims: The objective of this work was study the effect of Photodynamic Antimicrobial Chemotherapy using Toluidine blue as a photosensitizer on both yeast and mycelial cells of Paracoccidioides brasiliensis, isolated 18, and the possible mechanism involved on PACT action.
关键词： Toluidine Blue,Paracoccidioides brasiliensis,Photodynamic Antimicrobial Chemotherapy,dimorphism,fungus
更新于2025-09-23 15:22:29
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Changes of Intracellular Porphyrin, Reactive Oxygen Species, and Fatty Acids Profiles During Inactivation of Methicillin-Resistant Staphylococcus aureus by Antimicrobial Blue Light
摘要： Antimicrobial blue light (aBL) has attracted increasing interest for its antimicrobial properties. However, the underlying bactericidal mechanism has not yet been verified. One hypothesis is that aBL causes the excitation of intracellular chromophores; leading to the generation of reactive oxygen species (ROS) and the resultant oxidization of various biomolecules. Thus, monitoring the levels of redox-sensitive intracellular biomolecules such as coproporphyrins, as well as singlet oxygen and various ROS may help to uncover the physiological changes induced by aBL and aid in establishing the underlying mechanism of action. Furthermore, the identification of novel targets of ROS, such as fatty acids, is of potential significance from a therapeutic perspective. In this study, we sought to investigate the molecular impact of aBL treatment on methicillin-resistant Staphylococcus aureus (MRSA). The results showed that aBL (5–80 J/cm2) exhibited a bactericidal effect on MRSA, and almost no bacteria survived when 80 J/cm2 had been delivered. Further studies revealed that the concentrations of certain intracellular molecules varied in response to aBL irradiation. Coproporphyrin levels were found to decrease gradually, while ROS levels increased rapidly. Moreover, imaging revealed the emergence and increase of singlet oxygen molecules. Concomitantly, the lipid peroxidation product malondialdehyde (MDA) increased in abundance and intracellular K+ leakage was observed, indicating permeability of the cell membrane. Atomic force microscopy showed that the cell surface exhibited a coarse appearance. Finally, fatty acid profiles at different illumination levels were monitored by GC-MS. The relative amounts of three unsaturated fatty acids (C16:1, C20:1, and C20:4) were decreased in response to aBL irradiation, which likely played a key role in the aforementioned membrane injuries. Collectively, these data suggest that the cell membrane is a major target of ROS during aBL irradiation, causing alterations to membrane lipid profiles, and in particular to the unsaturated fatty acid component.
关键词： membrane injuries,coproporphyrin,lipids,methicillin-resistant Staphylococcus aureus,antimicrobial blue light,unsaturated fatty acids
更新于2025-09-23 15:22:29
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Photocatalytic and Antimicrobial Properties of Ag2O/TiO2 Heterojunction
摘要： Ag2O/TiO2 heterojunctions were prepared by a simple method, i.e., the grinding of argentous oxide with six different titania photocatalysts. The physicochemical properties of the obtained photocatalysts were characterized by diffuse-reflectance spectroscopy (DRS), X-ray powder diffraction (XRD) and scanning transmission electron microscopy (STEM) with an energy dispersive X-ray spectroscopy (EDS). The photocatalytic activity was investigated for the oxidative decomposition of acetic acid and methanol dehydrogenation under UV/vis irradiation and for the oxidative decomposition of phenol and 2-propanol under vis irradiation. Antimicrobial properties were tested for bacteria (Escherichia coli) and fungi (Candida albicans and Penicillium chrysogenum) under UV and vis irradiation and in the dark. Enhanced activity was observed under UV/vis (with synergism for fine anatase-containing samples) and vis irradiation for almost all samples. This suggests a hindered recombination of charge carriers by p-n heterojunction or Z-scheme mechanisms under UV irradiation and photo-excited electron transfer from Ag2O to TiO2 under vis irradiation. Improved antimicrobial properties were achieved, especially under vis irradiation, probably due to electrostatic attractions between the negative surface of microorganisms and the positively charged Ag2O.
关键词： Ag2O,antimicrobial properties,heterojunction,nanocomposites,heterogeneous photocatalysis,TiO2
更新于2025-09-23 15:22:29
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Antibacterial and natural room-light driven photocatalytic activities of CuO nanorods
摘要： The present work is aimed to establish the utility of CuO nanorods in diverse fields; from photocatalysis to antimicrobial applications. The CuO nanorods obtained via facile precipitation process (without any surfactant/ligand) depicted excellent photocatalytic activity when examined under natural diffused room light for the complete degradation of the organic pollutant, Rhodamine B. Neither any assistance of any oxidants nor an additional light sources (e.g., with high power, lower wavelength etc.) was required during the whole process. The antibacterial property was also examined for the CuO nanorods. Effects on the microbial growth were noteworthy; the maximum inhibition zone of 37 mm was noted against the Gram-negative E. coli. The most significant effect of the nanorods was depicted in the reduction of 99% of E. coli, 98% of S. flexneri and 93% of S. aureus cells. The suitable activity response of the nanorods establishes the efficacy of the room temperature synthesis process.
关键词： S.flexneri,E.coli,Antimicrobial,Photocatalysis,S. aureus,CuO nanorods
更新于2025-09-23 15:22:29
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Heteroleptic Ir(III)N6 Complexes with Long-Lived Triplet Excited States and In Vitro Photobiological Activities
摘要： A series of cationic heteroleptic iridium(III) complexes bearing tris-diimine ligands [Ir(phen)2(R-phen)]3+ (R-phen = phenanthroline (1), 3,8-diphenylphenanthroline (2), 3,8-dipyrenylphenanthroline (3), 3-phenylphenanthroline (4), 3-pyrenylphenanthroline (5), and 3,8-diphenylethynylphenanthroline (6)) were synthesized and characterized. These complexes possessed phen ligand-localized 1π,π* transitions below 300 nm, and charge transfer (1CT) and/or 1π,π* transitions between 300 and 520 nm. In 1, 2, 4, and 6, the low-energy bands were mixed 1CT/1π,π*. However, the increased π-donating ability of the pyrenyl substituent(s) in 3 and 5 split the low-energy bands into a pyrene-based 1π,π* transition at 300-380 nm and an intraligand charge transfer (1ILCT) transition at 380-520 nm. All complexes were emissive at room temperature in CH3CN, but the parentage of the emitting state varied depending on the R substituent(s). Complex 1 exhibited predominantly phen ligand-localized 3π,π* emission mixed with metal-to-ligand charge transfer (3MLCT) character, while the emission of 2, 4, and 6 was predominantly from the excited-state with 3π,π*/3ILCT/3MLCT character. The emission from 3 and 5 was dominated by pyrene-based 3π,π* states mixed with 3ILCT character. The different natures of the lowest triplet excited states were also reflected by the different spectral features and lifetimes of the triplet transient absorption of these complexes. Complexes 3 and 5 had singlet oxygen quantum yields as high as 81 and 72%, respectively. Both gave submicromolar phototoxicities toward cancer cells (SK-MEL-28 human melanoma) and bacteria (S. aureus and S. mutans) with visible light activation (and marginal to no photobiological activity with red light). Their visible-light phototherapeutic indices (PIs) toward SK-MEL-28 cells were 248 for 3 and >435 for 5; PIs were lower in bacteria (≤62) due to their inherent antimicrobial activities. Both complexes were shown to produce substantial amounts of intracellular reactive oxygen species (ROS), which may account for their photobiological activities.
关键词： photophysics,photodynamic therapy,long-lived triplet excited state,antimicrobial,photobiological activities,reactive oxygen species,heteroleptic Ir(III) trisdiimine complexes
更新于2025-09-23 15:22:29
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Handbook of Ecomaterials || Environmental Photocatalysis/Photocatalytic Decontamination
摘要： Water pollution caused by hazardous substances has become a global concern. Textile and dyestuff industries produce large amounts of wastewater containing various dye pollutants. Most azo dyes are nonbiodegradable and their release into the environment poses a major threat to the surrounding ecosystems. Remediation of organic aquatic pollutants by photocatalytic oxidation has proven to be an attractive promising technology among the advanced oxidation processes. Semiconductor photocatalysis is a topic of current interest mainly in view of its potential application in the mineralization of pollutants.
关键词： Pilot scale treatment,Heterogeneous photocatalysis,Air purification,Antimicrobial activity,Semiconductor oxides,Water pollution
更新于2025-09-23 15:21:21