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Controlled Synthesis of Triangular Silver Nanoplates by Gelatin–Chitosan Mixture and the Influence of Their Shape on Antibacterial Activity
摘要： Triangular silver nanoplates were prepared by using the seeding growth approach with the presence of citrate-stabilized silver seeds and a mixture of gelatin–chitosan as the protecting agent. By understanding the critical role of reaction components, the synthesis process was improved to prepare the triangular nanoplates with high yield and e?ciency. Di?erent morphologies of silver nanostructures, such as triangular nanoplates, hexagonal nanoprisms, or nanodisks, can be obtained by changing experimental parameters, including precursor AgNO3 volume, gelatin–chitosan concentration ratios, and the pH conditions. The edge lengths of triangular silver nanoplates were successfully controlled, primarily through the addition of silver nitrate under appropriate condition. As-prepared triangular silver nanoplates were characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS), UV-Vis, Fourier transform infrared spectroscopy (FT-IR), and X-Ray di?raction (XRD). Silver nanoplates had an average edge length of 65–80 nm depending on experimental conditions and exhibited a surface plasma resonance absorbance peak at 340, 450, and 700 nm. The speci?c interactions of gelatin and chitosan with triangular AgNPs were demonstrated by FT-IR. Based on the characterization, the growth mechanism of triangular silver nanoplates was theoretically proposed regarding the twinned crystal of the initial nanoparticle seeds and the crystal face-blocking role of the gelatin–chitosan mixture. Moreover, the antibacterial activity of triangular silver nanoplates was considerably improved in comparison with that of spherical shape when tested against Gram-positive and Gram-negative bacteria species, with 6.0 ug/mL of triangular silver nanoplates as the MBC (Minimum bactericidal concentration) for Escherichia coli and Vibrio cholera, and 8.0 ug/mL as the MBC for Staphylococcus aureus and Pseudomonas aeruginosa. The MIC (Minimum inhibitory concentration) of triangular Ag nanoplates was 4.0 ug/mL for E. coli, V. cholera, S. aureus, and P. aeruginosa.
关键词： seeding growth approach,triangular silver nanoplates,gelatin,antibacterial activity
更新于2025-09-16 10:30:52
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Sustainable Scientific Advancements modified Ag2O-ZnO thin films characterization and application of photocatalytic purification of carcinogenic dye in deionizer water and contaminated sea water solutions and Synthetic, Natural based Dye-Sensitized Solar Cells
摘要： The manuscript studied the preparation of ZnO as well as Ag2O-ZnO thin films deposited on glass substrates by spray pyrolysis approach at 500oC. The photocatalytic activity of Ag2O-ZnO nanocomposite material was studied via the Photodegradation reaction of Rhodamine B (Rh B) dye under UV-light irradiation in Deionizer water which shows high activity as compared by Contamination of sea water. The Zinc was Zincacetylacetonate (Zn C10 H14 O5) at the atomic concentration and then dissolved in the ethanol and Ag NO3 (0.1 M) dissolved in ethanol. The effect of silver Oxide - Zinc Oxide Nanocomposite material on the structural, surface morphological, electrical and optical properties of Ag2O-ZnO thin films were studied. HR-SEM and HR-TEM image shows exposed that the surface morphology of the films nanoflower shaped structure. The presence of Silver, Zinc and Oxygen are confirmed the presence of peaks, using EDS analysis. X-ray diffraction (XRD) patterns accepted the successful growth of high quality thin films which is polycrystalline nature. The PL analysis shows in Ag2O-ZnO is certified to the low recombination of electron-hole pairs by transfer of electrons and holes between ZnO and UV-Vis DRS analysis. The photocatalytic activity of Ag2O-ZnO nanocomposite material was studied from Photodegradation study of Rhodamine B (Rh B) dye under UV-light irradiation of Deionizer water was high activity that Contamination of sea water. As a reaction of this the material was found to be stable and reusable, which extends to a high antibacterial activity and the electrochemical study from synthetic based and Natural based DSSCS analysis showed increased current is short circuit by Ag2O-ZnO thin film nanocomposite material was industrial applications.
关键词： Spray pyrolysis,Photocatalytic activity,Electrochemical activity,Antibacterial activity
更新于2025-09-16 10:30:52
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Hierarchically porous surface of PEEK/nMCS composite created by femtosecond laser and incorporation of resveratrol exhibiting antibacterial performances and osteogenic activity in vitro
摘要： To further improve the surface properties of polyetheretherketone (PEEK)/nanoporous magnesium calcium silicate (nMCS) composite (PMC), hierarchically porous surface of PMC (PMCF) were created by femtosecond laser, and resveratrol (RV) was incorporated into the porous surface of PMCF (RV@PMCF). Compared to PMC with flat surface, PMCF contained not only two types of micropores with different sizes (around 20 μm and 0.5μm) but also nanopores (around 4 nm), which exhibited remarkably increase in surface roughness and protein adsorption. In addition, PMCF displayed a slow-release of RV while PMC showed a burst-release of RV into cell cultured medium. Moreover, compared with PMC and PMCF, RV@PMCF with antibacterial performances inhibited the growth of E. coli and S. aureus thanks to the release of RV. In addition, compared with PMC, PMCF and RV@PMCF significantly promoted adhesion and proliferation of rat bone mesenchymal stem cells (BMSC). Furthermore, compared with PMCF, RV@PMCF obviously enhanced the proliferation and osteogenic differentiation as well as bone related genes expressions of BMSC. The results demonstrated that PMCF with hierarchically porous surface and incorporating of RV displayed antibacterial performances and osteogenic activity in vitro, Therefore, as a drug-loaded implant, RV@PMCF with good cytocompatibility would have a big potential for applications in orthopaedic fields.
关键词： femtosecond laser,osteogenic activity,antibacterial performances,polyetheretherketone based composite,hierarchically porous surface
更新于2025-09-16 10:30:52
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Enhanced photocatalytic degradation and antibacterial performance by GO/CN/BiOI composites under LED light
摘要： GO/CN/BiOI composites were obtained by in-situ generation route and investigated in photocatalytic degradation and antibacterial. Detailed analysis of the photocatalyst was presented by XRD, TEM, SEM, XPS, FT-IR, Raman, DRS, photocurrent, EIS and LSCM. The synthesized GO/CN/BiOI composites showed good photocatalytic degradation and excellent antibacterial performance under LED light. The optimal composite could degrade 93% methyl orange (MO) in 60 min and 74% tetracycline (TC) in 100 min. In terms of antibacterial, GO/CN/BiOI composites could completely inactivated E. coli and S. aureus within 30 min. The mechanism of photocatalytic degradation and antibacterial activity was studied by trapping experiments, and h+ played an important role in the system. The improved photo-performance was attributed to the e?cient separation of electrons (e?) and holes (h+) in the composite. This work showed the GO/CN/BiOI composite is a potential photocatalyst in pollution removing and water disinfection.
关键词： Antibacterial,Photocatalytic degradation,GO/CN/BiOI,LED light
更新于2025-09-16 10:30:52
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Hydrogel-embedded gold nanorods activated by plasmonic photothermy with potent antimicrobial activity
摘要： Plasmonic photothermal therapy (PPTT) has been used as an alternative to chemotherapy for the elimination of resistant microorganisms; however, its in situ evaluation has not been well studied. In the present study, we assessed the antimicrobial activity of a chitosan-based hydrogel embedded with gold nanorods (Ch/AuNRs) using a low power infrared diode laser. The antibacterial activity was measured in both Gram-positive and –negative strains, including clinical isolates of multidrug-resistant pathogens. The cytotoxic effect, cellular proliferation, and the expression of the pro-inflammatory (IL-6 and TNF-α) and anti-inflammatory (IL-10) cytokines were quantified in a murine model of macrophages. Results showed a potent antimicrobial activity of the Ch/AuNRs with MICs ≤4 μg/mL, very low cytotoxicity with cell viability above 80%, and the macrophage proliferation was not affected for a period of 48 h. These results suggest that our Ch/AuNR-embedded hydrogel could be an option to locally control chronic nosocomial infections using PPTT.
关键词： inflammation,multidrug resistant,antifungal,photothermal therapy,gold nanorod,cytotoxicity,chitosan,antibacterial
更新于2025-09-16 10:30:52
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Influence of polymer molecular weight on the properties of in situ synthesized silver–methylcellulose nanocomposite films with a CO2 laser
摘要： We investigate the in?uence of polymer molecular weight on the properties of silver–methylcellulose (Ag–MC) nanocomposite ?lms synthesized by the irradiation of a CO2 laser. Although the reduction power of MC with a smaller molecular weight turns out to be stronger than that with a larger molecular weight in the solution phase, we do not see such a clear difference when MC is in the matrix phase. For the 30 s irradiation at the laser power of 0.8 W, the size of Ag nanoparticles (NPs) in the two types of MC matrix is similar, and it is about 30 nm. However, for the longer irradiation time at the same laser power, aggregation of Ag NPs set in, and it is more serious for the Ag–MC ?lm with MC of larger molecular weight. We also carry out the antibacterial test with the Ag–MC ?lms, and ?nd that the Ag–MC ?lm synthesized at the lower laser power and shorter irradiation time generally exhibits a stronger antibacterial effect.
关键词： antibacterial effect,polymer molecular weight,CO2 laser,silver–methylcellulose nanocomposite
更新于2025-09-12 10:27:22
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Extracellular biosynthesis of cadmium sulphide quantum dot using cell-free extract of Pseudomonas chlororaphis CHR05 and its antibacterial activity
摘要： For the ?rst time a novel aquatic bacterium belonging to strain of Pseudomonas chlororaphis was developed for the synthesis of cadmium sul?de quantum dots. The cadmium sulfate solution incubated with cell-free extract (CFE) of P. chlororaphis strain CHR05 to generate cadmium sul?de nanoparticles (CdSNps) which were characterized with combined spectroscopy and microscopy analyses. The preliminary con?rmation on the formation of CdSNps was done by UV–vis and ?uorescence analyses with the absorption and emission spectra at 435 and 475 nm, respectively. EDX pattern shows that the CdSNps are composed of the elementals Cd and S. Also, XRD analysis of the puri?ed nanoparticles con?rmed the formation of CdSNps. FE-SEM, TEM, and DLS analyzed the size and morphology of the CdSNps. The biosynthesis of CdSNps with the strategy of cell free extract was investigated under optimum conditions. After 24 h of incubation, the results showed that the novel isolated strain can produce spherical CdSNps with an average size of 6.7 ± 2.4 nm, after exposure to CdSO4 solution (2.5 mM) at pH 7.5 and 30 °C. The antibacterial activity CdSNps against some Gram-positive and -negative bacteria were determined using agar well di?usion method and microplate method which has growth-inhibitory e?ect all on tested bacteria.
关键词： CdSNps,Cell-free extract,P. chlororaphis strain CHR05,Antibacterial activity
更新于2025-09-12 10:27:22
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Copper nanoparticles obtained by laser ablation in liquids as bactericidal agent for dental applications
摘要： The dramatic increase of antibiotic-resistant bacteria is considered one of the greatest threats to human health at global scale. The antibacterial activity of noble metal nanoparticles, could be the solution against bacterial infectious diseases which currently do not respond to conventional treatments. In this work, copper nanoparticles were produced by laser ablation using two different lasers. A nanosecond laser operating at 532nm and a picosecond laser at 1064nm were used to ablate a copper target submerged in water and methyl alcohol. The obtained colloidal solutions consisted of copper oxide nanoparticles in suspension with diameters ranging from few nanometers to 45 nm. The nanoparticles formation process is highly influenced by laser parameters, but the solvent plays a crucial role on their characteristics. Cu oxide nanoparticles obtained in water present chain-like nanostructure, while those obtained in methyl alcohol are spherical with lower presence of oxide. All the obtained nanoparticles are crystalline and noticeably stable. Microbiology confirm their strong activity against Aggregatibacter actinomycetemcomitans. Cytocompatibility with human periodontal ligament stem cells is also confirmed. The biological assays evidence that ions release is not the main parameter responsible for the bactericidal activity of copper nanoparticles. Other factors such as oxidation state, size and crystallographic structure, have a greater influence on the process.
关键词： noble metal nanoparticles,laser ablation,copper nanoparticles,antibacterial effect
更新于2025-09-12 10:27:22
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A ruthenium nitrosyl-functionalized magnetic nanoplatform with near-infrared light-controlled nitric oxide delivery and photothermal effect for enhanced antitumor and antibacterial therapy
摘要： Developing spatiotemporal-controlled nitric oxide (NO) delivery nanoplatform is highly desirable for its biological applications as tumor inhibitor and antibacterial agent. In this study, a novel multifunctional magnetic nanoplatform {Fe3O4@PDA@Ru-NO@FA} (1) was developed for the near-infrared (NIR) light-controlled release of NO, in which a ruthenium nitrosyl (Ru-NO) donor and folic acid (FA)-directing group were covalently functionalized onto Fe3O4@PDA. Nanoplatform 1 preferentially accumulated in folate receptor-overexpressing cancer cell lines and magnetic field-guided tumor tissue, instantly released NO, and simultaneously produced a prominent photothermal effect upon 808 nm NIR light irradiation, leading to remarkable in vitro and in vivo antitumor efficacy. When nanoplatform 1 was treated only once, the potential MRI contrast agent was sufficient to significantly inhibit or eliminate the tumor tissues in living mice, thus offering opportunities for future NO-involved multimodal cancer therapy. In addition, a NO delivery nanoplatform {Fe3O4@PDA@Ru-NO} was imbedded in the matrix of chitosan (CS)-poly(vinyl alcohol) (PVA) material to develop a hybrid thermosensitive CS-PVA/NO hydrogels. The CS-PVA/NO hydrogels demonstrated mild (<150 mW cm-2) NIR light-controlled NO delivery and thus produced efficient antibacterial effect for both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. Therefore, these hydrogels feature potential as antibacterial dressings for treating wound bacterial infection.
关键词： nitric oxide delivery,magnetic nanoplatform,ruthenium nitrosyl donor,antitumor and antibacterial therapy,thermosensitive hydrogel
更新于2025-09-12 10:27:22
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Optically-controlled supramolecular self-assembly of an antibiotic for antibacterial regulation
摘要： We report a supramolecular photo-responsive antibiotic (azobenzene-norfloxacin/aCD). This supramolecule exhibited a higher ‘‘on–off’’ ratio of antibacterial ability than azobenzene-norfloxacin alone under UV irradiation. It offers an approach to efficiently regulate the activity of antibiotics by combining the supramolecular and light-regulating strategies together.
关键词： photo-responsive,antibiotic,antibacterial regulation,supramolecular,azobenzene-norfloxacin
更新于2025-09-12 10:27:22