Model Gram-negative Bacterium Research Articles

Photostability and photodynamic antimicrobial profile of dye extracts from four (4) plants: prospects for eco-friendly low-cost food disinfection and topical biomedical applications.

In this study, photostability and photodynamic antimicrobial performance of dye extracts from Hibiscus sabdariffa (HS) calyces, Sorghum bicolor (SB) leaf sheaths, Lawsonia inermis (LI) leaves and Curcuma longa (CL) roots were investigated in Acetate-HCl (AH) Buffer (pH 4.6), Tris Base-HCl (TBH) Buffer (pH 8.6), distilled water (dH2O), and Phosphate Buffer Saline (PBS, pH 7.2) using Bacillus subtilis as model for gram positive bacteria, Escherichia coli as model for gram negative bacteria, phage MS2 as model for non-envelope viruses and phage phi6 as model for envelope viruses including SARS CoV-2 which is the causative agent of COVID-19. Our results showed that the photostability of the dye extracts is in the decreasing order of LI > CL > SB > HS. The dye extract-HS is photostable in dH2O but bleaches in buffers-AH, TBH and PBS. The rate of bleaching is higher in AH compared to in TBH and PBS. The bleaching and buffers affected the photodynamic and non-photodynamic antimicrobial activity of the dye extracts. The photodynamic antibacterial activity of the dye extracts is in the decreasing order of CL > HS > LI > SB while the non-photodynamic antibacterial activity is in the decreasing order of LI > CL > HS > SB. The non-photodynamic antiviral activity pattern observed is the same as that of non-photodynamic antibacterial activity observed. However, the photodynamic antiviral activity of the dye extracts is in the decreasing order of CL > LI > HS > SB. Given their performance, the dye extracts maybe mostly suitable for environmental applications including fresh produce and food disinfection, sanitation of hands and contact surfaces where water can serve as diluent for the extracts and the microenvironment is free of salts.

Synergistic effects of hydrothermally decorated Ag nanoparticles over rGO for antibacterial activities

Antibacterial activity of the silver decorated reduced graphene oxide (Ag-rGO) nanocomposites have been investigated against E. coli as a model for gram-negative bacteria. The effect of temperature during the hydrothermal treatment of Ag-rGO nanocomposites synthesized by simultaneous reduction of GO and AgNO3 over the antibacterial activity has been studied. The composite samples were further reduced hydrothermally at different temperatures, viz. 100 °C, 150 °C, and 200 °C for 24 h to integrate silver nanoparticles (AgNPs) into rGO. Variations in the hydrothermal treatment temperature allowed alterations in the morphology and particle size of the AgNPs. The AgNPs grown at room temperature are in bunches and smaller sizes, whereas the hydrothermally treated samples have uniformly distributed bigger AgNPs. The particle size of AgNPs on rGO grows from 45 nm at room temperature to 65 nm and 220 nm in the hydrothermally treated samples at 150 °C and 200 °C, respectively. The antibacterial activity of the Ag-rGO composite has been observed to be size dependent. The Ag-rGO composite hydrothermally treated at 150 °C, having a particle size of ∼65 nm, has been observed to have the highest activity; the zone of inhibition is 3.4 ± 2.8 cm. The Ag nanocrystallite’s edges and defects in the rGO sheets together destroy the bacterial cells in a series of stages, ultimately resulting in cell death and high antibacterial activity.

Rapid and sensitive detection of gram-negative bacteria using surface-immobilized polymyxin B.

Although detection of gram-negative bacteria (GNB) in body fluids is important for clinical purpose, traditional gram staining and other recently developed methods have inherent limitations in terms of accuracy, sensitivity, and convenience. To overcome the weakness, this study proposed a method detecting GNB based on specific binding of polymyxin B (PMB) to lipopolysaccharides (LPS) of GNB. Fluorescent microscopy demonstrated that surface immobilized PMB using a silane coupling agent was possible to detect fluorescent signal produced by a single Escherichia coli (a model GNB) cell. Furthermore, the signal was selective enough to differentiate between GNB and gram-positive bacteria. The proposed method could detect three cells per ml within one hour, indicating the method was very sensitive and the sensing was rapid. These results suggest that highly multifold PMB binding on each GNB cell occurred, as millions of LPS are present on cell wall of a GNB cell. Importantly, the principle used in this study was realized in a microfluidic chip for a sample containing E. coli cells suspended in porcine plasma, demonstrating its potential application to practical uses. In conclusion, the proposed method was accurate, sensitive, and convenient for detecting GNB, and could be applied clinically.

N-Doped Carbon Nanoparticles as Antibacterial Agents on Escherichia coli: The Role of the Size and Chemical Composition of Nanoparticles

In the last years N-doped carbon nanoparticles have been shown to have improved antibacterial activity over the undoped nanomaterial, but it is difficult to find correlations between the structure of the nanoparticle and its antibacterial activity. This prevents us from proposing a clear antibacterial mechanism and makes it difficult to select materials with the best physical and chemical properties for use as antibacterial agents. With this purpose, here, we analyze the effect of, the size and the surface chemical composition of four N-doped carbon nanoparticles on the growth of Escherichia coli bacteria, used in this work as a model of Gram-negative bacteria. Our results indicated great antibacterial activity as the concentration of the carbon nanoparticles increased. The IC50 values obtained ranged between 23 and 34 μg/mL, the lowest values found in the literature for CNPs in the absence of metals. The reduction rate was analyzed using a Ligand-Substrate model based on Monod’s equation, which allows us to interpret the dependence of the nanoparticle-bacteria affinity with the nanomaterial structure. The results of the model indicate the contribution of two mechanisms, oxidative stress and the nanoknife in the antibacterial process on Escherichia coli bacteria.

ANTIMICROBIAL EFFECT OF SILVER NANOPARTICLE-BASED THIN FILMS

The global pandemic of disease COVID-19 caused by the pathogenic SARS-Cov-2 virus brought more interest in the public health community for known silver with its potential antimicrobial properties to fight infection. One of the ways to stop virus to protect community transmission is the application of nanotechnology of silver nanoparticles on the exposed surfaces of daily used materials in public, e.g., transportation, community spaces, hospitals, and everywhere where the potential infection load is increased. Published technology to coat AgNPs on surfaces differs in the preparation of nanocomposites and substrates, which results in different mechanical and antimicrobial properties. In our study, we focused on the properties of AgNPs prepared by HiTUS and PVD technology with a challenge to test the antimicrobial effect towards the model of gram-negative bacteria (Escherichia coli), fungi (Trichoderma harzianum) and related enteroviruses (Poliovirus and Coxsackie). All tested materials showed 59% or more growth inhibition of E. coli. Growth of T. harzianum was inhibited by 16% in the presence of AgTiB2 50W, and other materials caused 37% to 68% inhibition. Enteroviruses infection was completely inhibited after 1 hour of AgNPs treatment. Only Coxsackie A7 retained infection capability after 30 minutes of treatment with AgNPs. Moreover, the ICP-OES-measured amounts of silver released in cultivation media are lower than most published studies of silver nanoparticles with a comparable antimicrobial effect. Keeping silver concentration at the lowest possible limit is one of the most critical factors for producing environmentally safe antimicrobial materials for everyday use.

Antimicrobial activity of piezoelectric polymer: piezoelectricity as the reason for damaging bacterial membrane.

Cell stimulation using piezoelectric polymers, which is known as piezostimulation, is an innovative approach for designing antimicrobial protection. As an antibiotic-free and inorganic nanoparticle-free approach, it uses physical stimuli to target bacterial cells in a non-specific manner, which may be of great importance, particularly in the context of avoiding resistant bacterial strains. In this study, we prepared fully organic piezoelectric biodegradable films composed of poly-L-lactide (PLLA) and demonstrated their antimicrobial effect on S. epidermidis as a model of Gram-positive and E. coli as a model of Gram-negative bacteria. The PLLA films were either smooth and fabricated using simple melt- drawing or nanotextured, as self-standing nanotubes formed using the template-assisted method. The morphological differences between nanotextured and smooth films resulted in a larger surface area and better surface contact in nanotextured films, together with improved structural properties and better crystallinity, which were the main reasons for their better piezoelectric properties, and consequently stronger bactericidal effect. The comparison between the nanotextured surfaces with and without piezoelectric nature excluded the main role of morphology and directly confirmed piezoelectricity as the main reason for the observed antimicrobial affect. We also confirmed that piezo-stimulation using the antibacterial nanotextured film could damage the bacterial membrane as the main mechanism of action, while the contribution of pH changes and ROS generation was negligible. More importantly, the effect was selective toward the bacterial membrane and the same damage was not observed in human red blood cells, making the therapeutic use of these films possible.

3D coating layers of polyhydroquinone di-imidazopyridine (PIPD) fibers to improve their mechanical, interfacial and antimicrobial properties

The effect of growing CuO nanowires decorated with Ag nanoparticle in the presence of poly(dopamine) (PDA) as intermediate agent on PIPD fiber surface was evaluated. This treatment exhibited significant enhancement of the interfacial and mechanical performance, along with increment of the antimicrobial activity against E. coli as a model for Gram-negative bacteria. The scanning electron microscopy (SEM) validates the growth of CuO NWs and Ag NPs on the surface of PIPD fiber. The X-ray diffraction (XRD), The X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectroscopy and the ratio of weight loss analyses supported the above results. The interface shear strength (IFSS) between the PIPD fiber and epoxy resin was improved by 72%; and the coated Ag nanoparticles raised the fiber tensile strength (TS) by 13%. The influence of UV radiation and hydrothermal degradation on PIPD fiber was studied, and the UV and hydrothermal aging resistance were both increased by 15% and 22% respectively. The antimicrobial activity analysis results strong efficiency of the coated PIPD fibers by Ag NPs against gram negative bacteria E. coli.

Photochemistry of covalently bonded graphene oxide – Perylene diimide system for bacterial growth inhibition started by singlet oxygen

Two new composites containing perylene diimides derivates covalently bonded to graphene oxide were obtained and their antimicrobial properties were applied against Escherichia coli, a model of gram-negative bacteria. The perylene diimides were prepared by condensating perylene dianhydride with ethyldiamine (PEDI2) or decyldiamine (PEDI10) and then, a SOCl2 modified GO sample reacted with perylene diimides, originating the respective covalently bonded GO/PEDI2 and GO/PEDI10. Semi-empirical calculations with PM6-DH2X (MOPAC 2016) confirmed the photophysical results and showed that perylene diimides could form three different structures when bonded to GO: (1) parallel to GO, forming π-stacking interaction; (2) parallel to GO, but not superimposed π-systems (pns-π), and; (3) perpendicular to the GO molecular plane (T-shape). The photophysical studies showed that both GO/PEDI2 and GO/PEDI10 composites were able to generate singlet oxygen (1O2) when perylene diimides did not form π-stacking with GO. Finally, the photochemical reactivities of such covalently bonded composites were confirmed by the increased bacterial inhibition when E. coli (more than 80 %) is irradiated in the visible part of the electromagnetic spectrum when compared to dark conditions GO.

Prolonged antimicrobial activity of silver core-carbon shell nanoparticles

Ag nanoparticles present good antimicrobial activity but with a potential toxicity to the cell, which limits the application. To address this issue, in this work, carbon-encapsulated sliver nanocapsules (Ag@C nanocapsules) were prepared by evaporating pure Ag ingot with the modified arc-discharge technique, and the Ag@C nanocapsules were acidified with nitric acid subsequently to facilitate the silver ion to release. Finally, Ag@C nanocapsules displayed a good and sustained antimicrobial activity against E. coli as a model of Gram-negative bacteria, due to the long-term release of sliver ions from Ag@C nanocapsules. The results obtained in this work indicate that the Ag@C nanocapsules may be a suitable nanomaterial for the bactericidal application.

Choosing an Optimal Sample Preparation in Caulobacter crescentus for Untargeted Metabolomics Approaches

Untargeted metabolomics aims to provide a global picture of the metabolites present in the system under study. To this end, making a careful choice of sample preparation is mandatory to obtain reliable and reproducible biological information. In this study, eight different sample preparation techniques were evaluated using Caulobacter crescentus as a model for Gram-negative bacteria. Two cell retrieval systems, two quenching and extraction solvents, and two cell disruption procedures were combined in a full factorial experimental design. To fully exploit the multivariate structure of the generated data, the ANOVA multiblock orthogonal partial least squares (AMOPLS) algorithm was employed to decompose the contribution of each factor studied and their potential interactions for a set of annotated metabolites. All main effects of the factors studied were found to have a significant contribution on the total observed variability. Cell retrieval, quenching and extraction solvent, and cell disrupting mechanism accounted respectively for 27.6%, 8.4%, and 7.0% of the total variability. The reproducibility and metabolome coverage of the sample preparation procedures were then compared and evaluated in terms of relative standard deviation (RSD) on the area for the detected metabolites. The protocol showing the best performance in terms of recovery, versatility, and variability was centrifugation for cell retrieval, using MeOH:H2O (8:2) as quenching and extraction solvent, and freeze-thaw cycles as the cell disrupting mechanism.

Spectral Characterization and Antibacterial Activity of Synthesis Graphene Oxide Nanosheets

Graphene based materials have wide potential applications in biology, biomedical, agriculture environmental and biotechnology. Graphene Oxide (GO) is one of those substances and has a promising material as antimicrobial agents. In this work, the GO nanosheets have been synthesized by novel, easy, and efficient technique is simplified Hummer's method. The spectral properties of the synthesis GO nanosheets were characterized by using Raman, FTIR, and UV-Vis techniques. The Raman spectroscopy has been used to measure number of layers (sheets), grain size, and to identify the ordered and disordered structure of GO nanosheets. Fourier Transform-Infrared spectroscopy (FTIR) has confirmed the presence of the oxygen containing functional groups of the GO nanosheets. The Ultraviolet-Visible (UV-Vis) absorption spectrum shows two peaks, one in the UV region and the other band in visible region. The purpose of this work is to inspect the antibacterial activities of GO nanosheets, which has been synthesized by this novel way (simplified Hummer's method). It was tested against two microorganisms, Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) as model of Gram-negative bacteria and Gram-positive bacteria, respectively. Bacteriological studies were achieved by minimum inhibitory concentration (MIC), and cell viability analysis. The MIC showed the lowest concentration inhibits the bacterial growth of GO nanosheets, which is observed for E. coli was 125 μg/ml and 62.5 μg/ml for S. aureus. The cell viability analysis measured by florescent microscope has been confirmed the damage, which has been occurred on bacterial nucleic acid for the two types of bacteria.

A simple, rapid and cost-effective colorimetric assay based on the 4-mercaptophenylboronic acid functionalized silver nanoparticles for bacteria monitoring

The rapid and cost- effective detection of bacteria is of great importance in various fields. Herein, a novel colorimetric detection method for Gram-negative bacteria based on the inhibition of the aggregation of 4-mercaptophenylboronic acid functionalized AgNPs (MPBA-AgNPs) was demonstrated. MPBA, one of the boronic acid derivative, which could react with the cis-diol groups contained in saccharides on the bacteria cells, was used as the recognition molecule for bacteria detection. The aggregation of MPBA-AgNPs could be inhibited by bacterial cells, resulting in different color change, which could be distinguished with UV–vis spectrometer and the naked eye. The concentration of E. coli, a model of Gram-negative bacteria, could be determined in a dynamic range from 5 × 104 cfu mL−1 to 1 × 107 cfu mL−1 with a LOD of 0.9 × 104 cfu mL−1 with fast response of 20 min. Meanwhile, a smartphone based measuring analysis was established to make it suitable for routine laboratory applications. Moreover, the concept of the MPBA-AgNPs based colorimetric strategy could be expanded to other Gram-negative bacteria suggesting a universal platform for bacterial assay.

Preparation of azo-dye sensitized TiO2 photocatalyst for inhibition of E-Coli bacteria under visible light irradiation

The antibacterial activity of dye-sensitized semiconductor titanium dioxide films containing 4-{(E)-[4-(dimethylamino) phenyl] diazenyl} benzoic acid azo dye against E. coli was investigated as a model for Gram-negative bacteria. Several reports have been reported where metal complex have is used as dye, though sensitization of organic dye has not yet reported. These azo-dye sensitized TiO2 nanomaterials were characterized by XRD, SEM and UV-visible spectra. Spherical nature of TiO2 and sensitization can be seen from SEM images, XRD data suggest the particles in anatase form, photo switching of Azo-dye was studied using UV-Visible spectra. The bactericidal effects of films under UV-visible light irradiation were measured, experimental results indicate that these films inhibit the growth of Escherichia coli under UV light irradiation, the irradiation time could be considerably reduced and the bactericidal efficiency is related to the coverage of TiO2 films. With the increase in concentration of dye the activity was also increased.

Shape Changes and Interaction Mechanism of Escherichia coli Cells Treated with Sericin and Use of a Sericin-Based Hydrogel for Wound Healing.

To verify the interaction mechanism between sericin and Escherichia coli, especially the morphological and structural changes in the bacterial cells, the antimicrobial activity of sericin against E. coli as a model for Gram-negative bacteria was investigated. The antibacterial activity of sericin on E. coli and the interaction mechanism were investigated in this study by analyzing the growth, integrity, and morphology of the bacterial cells following treatment with sericin. The changes in morphology and cellular compositions of bacterial cells treated with sericin were observed by an inverted fluorescence microscope, scanning electron microscopy, and transmission electron microscopy. Changes in electrical conductivity, total sugar concentration of the broth for the bacteria, and protein expression of the bacteria were determined to investigate the permeability of the cell membrane. A sericin-based hydrogel was prepared for an in vivo study of wound dressing. The results showed that the antibacterial activity of the hydrogel increased with the increase in the concentration of sericin from 10 g/liter to 40 g/liter. The introduction of sericin induces membrane blebbing of E. coli cells caused by antibiotic action on the cell membrane. The cytoplasm shrinkage phenomenon was accompanied by blurring of the membrane wall boundaries. When E. coli cells were treated with sericin, release of intracellular components quickly increased. The electrical conductivity assay indicated that the charged ions are reduced after exposure to sericin so that the integrity of the cell membrane is weakened and metabolism is blocked. In addition, sodium dodecyl sulfate-polyacrylamide gel electrophoresis demonstrated that sericin hinders the expression of bacterial protein. Sericin may damage the integrity of the bacterial cell membrane, thereby eventually inhibiting the growth and reproduction of E. coli Compared to sterile gauze, the sericin-based hydrogel promoted fibroblast cell proliferation and accelerated the formation of granulation tissues and neovessels. The specific relationship and interaction mechanism between sericin and E. coli cells were investigated and elucidated. The results show that after 12 h of treatment, sericin molecules induce membrane blebbing of E. coli cells, and the bacteria show decreases in liquidity and permeability of biological membrane, resulting in alterations in the conductivity of the culture medium and the integrity of the outer membrane. The subsequent in vivo results demonstrate that the sericin-poly(N-isopropylacrylamide-N,N'-methylene-bis-acrylamide [NIPAm-MBA]) hydrogel accelerated wound healing compared to that with sterile gauze, which is a beneficial result for future applications in clinical medicine and the textile, food, and coating industries.

Antibacterial mechanism of polyacrylonitrile fiber with organophosphorus groups against Escherichia coli

A series of novel polyacrylonitrile fibers (PANF) with organophosphorus groups (OPh-PANF) showing unique antibacterial activities were synthesized in our previous studies. To understand the antibacterial mechanism of OPh-PANF, E. coli was selected as the model of Gram-negative bacteria and a list of biological experiments were conducted and analyzed in the current study. Results from scanning electron microscope (SEM), transmission electron microscope (TEM) and flow cytometry (FCM) analyses showed that the integrity of the cell membrane was severely damaged, causing a large number of intracellular potassium ions and macromolecular proteins leaking out of the cells. In addition, OPh-PANF can disrupt the intracellular enzyme systems by FCM analysis. Results from sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and mass spectrometry (MS) analyses showed that after exposure to OPh-PANF, specific protein bands disappeared or weakened, indicating that OPh-PANF mainly inhibited synthesis and expression of structural proteins (OmpA) and functional proteins (HtpG, AhpC, FNM, CAD). On the basis of the above results, an antibacterial mechanism was proposed for OPh-PANF against E. coli. When OPh-PANF was exposed to E. coli, the first step was to adsorb E. coli on its surface, then organophosphorus groups pre-grafted on the fibers began to execute the function of killing bacteria through three combined ways, i.e. destruction of cell membrane structure, disordering of enzyme system and inhibition of protein synthesis.

Inactivation of Pseudomonas aeruginosa by zinc oxide nanoparticles in aqueous solution

Since ZnO nanoparticles (ZnO-NPs) exhibit strong antibacterial activities on a broad spectrum of bacteria the aim of this study was to evaluate the antimicrobial activity of Zno-NPs against Pseudomonas aeruginosa as a model for gram-negative bacteria.

Gold Nanoparticles as Dual Functional Sensor to Detect E.coliDH5α as a Model for Gram‐negative Bacteria

Abstract4‐aminothiophenol‐modified gold nanoparticles (PATP‐AuNPs) were used as colorimetric and Surface Enhanced Raman Scattering (SERS) probes for the sensitive detection of Escherichia coliDH5α, as a model for Gram‐negative bacteria. The nano‐probes were easy to prepare through Au‐S bonding. Under optimized conditions, the PATP‐AuNPs surface with positive charge can bind with negatively charged E.coliDH5α via electrostatic adhesion, resulting in a quick color change from red to blue, and also a dramatic SERS signal enhancement from thousands of AuNPs aggregated on the surface of bacteria, which was utilized for both colorimetric and SERS detection of E.coliDH5α. For colorimetric analysis, it is the first time that the classical partial least square (PLS) regression was utilized to deal with the relationship between adsorption and E.coliDH5α concentrations. Excellent linear relationship was observed from 1.1 x 107 to 1.3 x 108 cfu mL‐1 with the average relative error (ARE) of 5.430, which was more accurate than the traditional extinction ration method. When coupled with confocal Raman microscope, this PATP‐AuNPs probes could be used to detection SERS signals produced from even one single bacterium. This bioassay is rapid, less expensive and convenient for bacteria detection and analysis. Therefore, PATP‐AuNPs system as a novel, versatile, on‐site and real‐time Gram‐negative bacteria sensor, would have a wide range of practical applications.

Fabrication and Characterization of Antibacterial Ag-TiO<sub>2</sub> Thin Films Prepared by DC Magnetron Co-Sputtering Technique

In this study, silver-doped titanium dioxide (Ag-TiO2) thin films were prepared co-sputtering technique in order to promote photo-induced antibacterial applications. The high-purity Ag (99.995%) and Ti (99.995%) were simultaneously co-sputtering on BK7 glass and silicon (100) wafers substrate. The structure, morphology, surface roughness and optical properties were characterized by grazing-incidence X-ray diffraction (GIXRD), field-emission scanning electron microscopy (FE-SEM) and UV-Vis spectrophotometer, respectively. The results showed that the as-deposited Ag-TiO2 thin films had high transparency in the visible range. The antibacterial activity was studied in the presence and in the absence of UV irradiation against Escherichia coli as a model for Gram-negative bacteria. The results indicated that, in comparison to conventional TiO2 films, the Ag-TiO2 thin films exhibited excellent antibacterial properties under the UV illumination.

Powder Characteristics and Biocidal Activity of the MnOx–WO3–TiO2 System Synthesized by a Sol–Gel Method for Antifouling Agents

The TiO₂-system powders were investigated with respect to the crystallinity and the microstructure. The biocidal activity increased from TiO₂ to binary MnOx-TiO₂ to ternary MnOx-WO₃-TiO₂ against Vibrio fischeri as a model of Gram-negative bacteria. Anatase and rutile TiO₂ were not toxic even at 200 mg/L, but anatase has been observed in bacterial growth inhibition due to the different electronic band (lattice) structure. All materials containing manganese oxides were toxic: the toxicity correlation (EC₅₀) of MnOx-WO₃ and MnOx-WO₃-TiO₂ was 7.0, 1.8 ppm, respectively. The high antifouling activity of MnOx-WO₃-TiO₂ was attributed to its redox potential and soluble metal ions originating from tungsten oxides according to the improvements in the powder characteristics.

Hydroxyapatites and Europium(III) Doped Hydroxyapatites as a Carrier of Silver Nanoparticles and Their Antimicrobial Activity

Hydroxyapatites (Ca10(PO4)6(OH)2 and Eu3+:Ca10(PO4)6(OH)2) were synthesized by aqueous synthesis route. Hydroxyapatites were impregnated with silver ions that were subsequently reduced. XRD, TEM, and SAED measurements were used in order to determine the crystal structure and morphology of the final products. The results showed the well crystallized hydroxyapatite grains with diameter of about 35 nm and with silver nanoparticles on their surface. The antimicrobial activity of the nanoparticles against: Staphylococcus aureus ATCC 6538 as model of the Gram-positive bacteria, Escherichia coli ATCC 11229, and Klebsiella pneumoniae ATCC 4352 as model of Gram-negative bacteria, were shown with the best activity against K. pneumoniae. These nanocomposite powders can be a promising antimicrobial agent and a fluorescent material for biodetection due to their optical and bioactive properties.