Formation Of Spherical Nanoparticles Research Articles

Electrical conductivity improvement of Fe doped ZnO nanopowders

The chemical co-precipitation process was used for the synthesis of Fe-doped ZnO nanopowders (ZnO:Fe) with varying doping concentrations from 0% to 10 %. Doping with iron caused significant alterations in the physical properties of ZnO nanopowders. The XRD analysis revealed that Fe introduction forms a secondary phase of spinel ZnFe2O4 for doping concentration higher than 1%. The average crystallite size was proven to decrease with the increase in Fe concentration. SEM images showed the formation of spherical nanoparticles, where the average grain size decreased with doping. The Fe incorporation into the ZnO host lattice was also confirmed by FTIR and Raman spectroscopy. The optical properties were strongly influenced by Fe doping. The dielectric parameters were subsequently investigated as a function of frequency and composition. The observed dielectric dispersion was interpreted on the basis of Maxwell-Wagner interfacial model and Koops phenomenological theory. Overall, Fe doping improved the electrical conductivity of ZnO nanopowders.

A bioinspired strategy for poly(3,4-ethylenedioxypyrrole) films with strong water adhesion

Abstract Using a bioinspired approach, we prepare poly(3,4-ethylenedioxypyrrole) (PEDOP) films with parahydrophobic properties, characterized by high apparent water contact angle and strong water adhesion. The films are made by electropolymerization and the influence of substitution by an alkyl chain of various length (from C4H9 to C14H29) on the 3,4-ethylenedioxy-bridge is reported. More precisely, the best properties are obtained from a length of C12H25 due to the formation of spherical nanoparticles.

Synthesis and characterization of polyaniline-nickel oxide nanocomposites for electrochemical supercapacitor

Polyaniline-nickel oxide (PANI/NiO) nanocomposites synthesized successfully by chemical polymerization method. Prepared nanocomposites (50%) were investigated by X-Ray Diffraction (XRD) and Transmission Electron Microscopy (TEM). XRD results revealed that, NiO retain its structure even though it is dispersed in PANI during polymerization. TEM image of PANI/NiO nanocomposites shows predominant formation of spherical nanoparticles within PANI matrix of size 20 nm. The electrochemical properties of NiO, PANI/NiO electrode having diameter of about 4.2 mm and height is 4.7 cm examined through cyclic voltammetry (CV). The electrochemical results were improved for synthesized NiO electrode which demonstrated that NiO is promising electrode material for high performance supercapacitor applications.

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.

XAS Microstructure Analysis of Manganese Doped Zinc Sulphide Nanophosphor

This paper reports wet chemical synthesis of Manganese doped Zinc Sulphide Nanophosphors capped with polyvinyl alcohol (PVA) while varying the concentrations of the dopant and capping agent to explore the optoelectronic and microstructural properties. Optical and morphological comparative studies reveal strongest room temperature orange luminescence (∼591 nm) of 10% dopant concentration with 2% capping agent in the ZnS host lattice and irregularly spherical nanoparticles formation (∼29 nm). Further, structural and elemental study of the sample reveals uncontaminated hexagonal wurtzite nanoparticles with least structural distortion due to dopant induced substitutional defect. The XANES and EXAFS microstructure analysis confirm the creation of substitutional defect and comparable Zn-S and Mn-S bond lengths such that Mn luminescent centers are created. Hence, the detailed study of the material indicates its high efficiency, proving its ability to be explored as a strong candidate for Mn: ZnS based UV Photodetector devices.

Photophysical and Optical Properties of Semiconducting Polymer Nanoparticles Prepared from Hyaluronic Acid and Polysorbate 80.

A nanoprecipitation procedure was utilized to prepare novel diketopyrrolopyrrole-based semiconducting polymer nanoparticles (SPNs) with hyaluronic acid (HA) and polysorbate 80. The nanoprecipitation led to the formation of spherical nanoparticles with average diameters ranging from 100 to 200 nm, and a careful control over the structure of the parent conjugated polymers was performed to probe the influence of π-conjugation on the final photophysical and thermal stability of the resulting SPNs. Upon generation of a series of novel SPNs, the optical and photophysical properties of the new nanomaterials were probed in solution using various techniques including transmission electron microscopy, dynamic light scattering, small-angle neutron scattering, transient absorption, and UV–vis spectroscopy. A careful comparison was performed between the different SPNs to evaluate their excited-state dynamics and photophysical properties, both before and after nanoprecipitation. Interestingly, although soluble in organic solution, the nanoparticles were found to exhibit aggregative behavior, resulting in SPNs that exhibit excited-state behaviors that are very similar to aggregated polymer solutions. Based on these findings, the formation of HA- and polysorbate 80-based nanoparticles does not influence the photophysical properties of the conjugated polymers, thus opening new opportunities for the design of bioimaging agents and nanomaterials for health-related applications.

Synthesis of gold nanoparticles by annealing its thin film under a layer of fluoropolymer coating

Gold thin films were deposited on the substrate of silicon and fused silica by method of Vacuum Gas Jet Deposition. Obtained films were coated with a fluoropolymer and annealed in a rarefied inert gas atmosphere at the temperature of 400 °C. The film morphology and composite were studied by the scanning electron microscopy. Optical properties of obtained coatings and composites were investigated. The influence of the fluoropolymer coating on formation of gold nanoparticles in the result of annealing of its thin films is established. The critical gold film thickness coated with fluoropolymer is determined, below which the presence of fluoropolymer lends to the formation of spherical nanoparticles during annealing of the composite in a studied range of parameters.

Fabrication of silicon carbide nanoparticles using picosecond pulsed laser ablation in acetone with characterizations from TEM and XRD

We fabricated SiC nanoparticles (NPs) using a laser ablation method in acetone with a picosecond pulsed laser and characterized the resulting sizes, shapes, and crystal structures using transmission electron microscopy (TEM) and X-ray diffraction (XRD). We revealed two formation processes for the SiC NPs. The main process was the formation of spherical NPs with diameters primarily less than 10 nm. The crystal structure was 3C-SiC, which did not depend on a target polytype. Therefore, it is concluded that these NPs are grown from atomic molecules that disassociate from targets in the ablation process. As a result of a Rietbelt analysis of the XRD patterns, we clearly found that almost all NPs were single crystals. In addition, a stacking fault in the crystal was observed in the TEM image, which affects the XRD pattern. The other process was the formation of NPs with diameters from 30 to 80 nm with crystal structures that were the same as the targets. This indicates that these NPs were generated as fragments of the target. Our findings are useful for applications of SiC NPs to selectively control their size, shape, and crystal structure using laser ablation.

Synthesis, characterization and cytotoxicity of chitosan-coated Fe3O4 nanoparticles functionalized with ascorbic acid for biomedical applications

Iron oxide magnetic nanoparticles (Fe3O4 NPs) are used to drive and to promote sustained release of drugs in target sites. Biocompatibility and superparamagnetic behaviour are important features to the successful biomedical applications of Fe3O4 NPs. In this study, Fe3O4 NPs were synthesized by the co-precipitation method and coated with chitosan (CS) containing ascorbic acid (AA), allowing formation of Fe3O4@CS-AA NPs. The antioxidant AA was used as a drug model. The synthesized NPs were characterized by different techniques. The results showed the formation of spherical nanoparticles with average diameter of 67.22 ± 0.82 nm, at solid state, as analysed by atomic force microscopy (AFM). The NPs were found to have a superparamagnetic behaviour at room temperature, and the presence of CS-AA on the surface of Fe3O4 NPs did not affect the superparamagnetic behaviour of the nanoparticles. The in vitro AA release assay showed a sustained release of the model drug from Fe3O4@CS-AA NPs for at least 48 h. In addition, cytotoxicity assays for Fe3O4 NPs and Fe3O4@CS-AA NPs did not show significant toxicity towards mammary epithelium (MCF-10A) cell line after 24 h of incubation. This present study demonstrated the successful synthesis of superparamagnetic and biocompatible Fe3O4@CS-AA NPs, which are able to release the model drug in a sustained manner. Thus, this nanomaterial might act as a nanocarrier in target drug release.

A facile one pot flash combustion synthesis of ZnO nanoparticles and their characterizations for photocatalytic applications

Herein, we have facilely synthesized high purity ZnO nanoparticles by flash combustion technique in presence of different citric acid (CA) content. X-ray diffraction study rules out the existence of any extra phase except single hexagonal phase of ZnO. Further, crystallite size, dislocation density and strain values were estimated, and the crystallite size was found to be reduced from 20to 10 nm with rising the concentration of CA. Vibrational study also confirm the single phase in accordance with XRD results and revealed that the modes of vibration are slightly shifted owing to quantum size effect and relaxed nanostructure formation. To confirm the purity of synthesized ZnO the energy dispersive X-ray spectroscopy was carried out which confirm the high purity of synthesized products. Spherical nanoparticles (SNPs) morphology was confirmed through scanning electron microscopy and the size is reduced with raising the concentration of CA. TEM study was also carried out which clearly shows the formation of spherical nanoparticles (SNPs) and the mean size is around 10 nm for 1 g CA:ZnO and < 6 nm for 10 g CA:ZnO samples. The blue shift in absorption edge was noticed in DR spectra with raising the CA concentrations and the energy gap was estimated using Kubelka-Munk theory. The estimated direct energy gap of ZnO SNPs was noticed to be increased from 3.25 to 3.28 eV. An enhancement in dielectric constant from 14 to 17 and ac conductivity was observed with raising the CA content. Furthermore, the prepared SNPs of ZnO were subjected to photocatalytic study from application point of view. The photocatalytic performance of the prepared materials is found to be improved several times. All results displayed that the CA is playing the vital role in improving the optoelectronic and photocatalytic performance of ZnO and hence will be more applicable.

Microwave Assisted Sol-Gel Synthesis of Silica-Spider Silk Composites.

This study introduces a simple and environmentally friendly method to synthesize silica-protein nanocomposite materials using microwave energy to solubilize hydrophobic protein in an aqueous solution of pre-hydrolyzed organo- or fluoro-silane. Sol-gel functionality can be enhanced through biomacromolecule incorporation to tune mechanical properties, surface energy, and biocompatibility. Here, synthetic spider silk protein and organo- and fluoro-silane precursors were dissolved and mixed in weakly acidic aqueous solution using microwave technology. Scanning electron microscopy (SEM) and Atomic force microscopy (AFM) images revealed the formation of spherical nanoparticles with sizes ranging from 100 to 500 nm depending, in part, on silane fluoro- or organo-side chain chemistry. The silane-protein interaction in the nanocomposite was assessed through infrared spectroscopy. Deconvoluted ATR-FTIR (Attenuated total reflectance Fourier-transform infrared spectroscopy) spectra revealed silane chemistry-specific conformational changes in the protein-silane nanocomposites. Relative to microwave-solubilized spider silk protein, the β structure content increased by 14% in the spider silk-organo-silica nanocomposites, but decreased by a net 20% in the spider silk-fluoro-silica nanocomposites. Methods of tuning the secondary structures, and in particular β-sheets that are the cross-linking moieties in spider silks and other self-assembling fibrillar proteins, may provide a unique means to promote protein interactions, favor subsequent epitaxial growth process, and enhance the properties of the protein-silane nanocomposites.

Fabrication and characterization of microwave assisted carboxymethyl cellulose-gelatin silver nanoparticles imbibed hydrogel: Its evaluation as dye degradation

The hybrid hydrogel of carboxymethyl cellulose (CMC) and gelatin was synthesized by grafting of poly(acrylic acid) chains in the presence of ammonium persulphate (APS) as initiator and N, N′–methylenebisacrylamide (MBA) as cross-linker in aqueous medium using microwave irradiation method. The hydrogel showed swelling ratio (SR) of 80 g/g at pH 10.0. FTIR of hydrogel confirmed the interaction of CMC and gelatin through cross-linker MBA to form a three-dimensional network. SEM studies further confirmed the three dimensional cross-linked porous structure of synthesized hydrogel. The addition of gelatin to CMC modified the network architecture and contributed to improved mechanical and thermal properties. The characteristic surface plasmon resonance (SPR) of nanosilver was observed at 414 nm. TEM images showed the formation of spherical nanoparticles with mean particle size of 12 nm and zeta potential value is +34.12 mV, indicated the good stability of silver nanoparticles. XRD and SAED pattern agreed with fcc crystalline structure of silver nanoparticles within porous network. The silver nanoparticles loaded hybrid hydrogel exhibited a promising catalytic activity for degradation of congo-red and rhodamine B dyes.

Encapsulation of epigallocatechin-3-gallate into albumin nanoparticles improves pharmacokinetic and bioavailability in rat model.

In the present study, we fabricated epigallocatechin-3-gallate (EGCG) loaded albumin nanoparticles (Alb-NP-EGCG) to enhance bioavailability and improve pharmacokinetic parameters of EGCG. The physicochemical properties of the Alb-NP-EGCG were studied using scanning electron microscopy, differential scanning calorimetry, powder X-ray diffraction and in vitro release studies. Characterization of Alb-NP-EGCG indicated the formation of spherical nanoparticles with no drug and excipient interaction. Alb-NP-EGCG showed a high drug loading capacity of 92%. Further, in vitro study showed a sustained release of EGCG from Alb-NP-EGCG over a period of 48h. Mathematical modeling and release kinetics indicated that the Alb-NP-EGCG followed zero order kinetic and EGCG was released via fickian diffusion method. In vivo bioavailability and distribution of Alb-NP-EGCG showed an enhanced plasma concentration of EGCG with 1.5 fold increase along with prolonged T 1/2 of 15.6h in the system when compared with the free EGCG. All this study demonstrated the fabrication of EGCG loaded albumin nanoparticles which favored the slow and sustained release of EGCG with improved pharmacokinetics and bioavailability thereby prolonging the action of EGCG. Additional acute and sub-acute toxicity test of the Alb-NP-EGCG demonstrated the safety of the Alb-NP-EGCG. Therefore, the Alb-NP-EGCG could be a promising drug delivery system for EGCG.

Influence of ammonium nitrate concentration on structural evolution and optical properties tuning of CdS nanoparticles synthesized by precipitation method

Cadmium sulfide (CdS) shows vital applications in many fields, such as electronic devices, catalysis, and solar cell. In this study, CdS nanoparticles have been synthesized by a simple chemical precipitation method using cadmium chloride as Cd source, thiourea as S source and ammonium nitrate (NH4NO3) as a complexing agent. The effect of NH4NO3 concentration on the structural, optical and thermal properties of the CdS nanoparticles annealed at 160 °C were extensively studied using X-ray Diffractometer (XRD), Fourier transform infrared (FTIR), UV–visible spectrophotometer, scanning electron microscope (SEM), thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). The FTIR result shows that the Cd-S stretching vibration band occurred in the range of 400 to 700 cm−1. The XRD patterns reveal a phase transformation from cubic to hexagonal with crystallinity improvement as the NH4NO3 concentration increases. The average nanocrystallite size estimated by the Scherrer method lying in the 2–11 nm range, and the size is tunable by varying the NH4NO3 concentration. The SEM images exhibit the formation of spherical nanoparticles. Blue shift of the absorption edge is observed on the UV–visible absorption spectra due to the presence of quantum confinement effects. The calculated optical band gap from the Tauc plot is higher than bulk CdS and becomes wider as the crystallite size decreases. Moreover, the TGA and DSC results reveal that the obtained CdS with smaller crystallite size exhibits improved thermal stability. The properties obtained in this study show that the ammonium nitrate is versatile to be used for generating and tuning the desired structural and optical properties of the CdS nanoparticles.

Synthesis and characterization of β-cyclodextrin/poly(o-phenylenediamine) inclusion complex

The present short communication highlights the synthesis of poly(o-phenylenediamine) (POPD)/β-cyclodextrin inclusion complex via ultrasound-assisted in-situ polymerization of o-phenylenediamine in the former. The inclusion complexes were characterized for their spectral and morphological properties. IR and UV visible studies confirmed the increase in the extent of interaction between the two moieties upon increasing the loading of POPD while XRD revealed a crystalline morphology. TEM revealed formation of spherical nanoparticles of controlled morphology. The inclusion complexes hold potential to be utilized for designing drug delivery vehicles.

Synthesis of polyynes by laser ablation of graphite in ethanol

In this work Polyynes was synthesized by pulse laser ablation of graphite target in ethanol solution. UV-Visible Spectrophotometer, Fourier Transform Infrared Spectroscopy (FTIR) and Transmission electron microscopy (TEM) were used to study the optical absorption, chemical bonding, particle size and the morphology. UV absorption peaks coincide with the electronic transitions corresponding to linear hydrogen – capped polyyne (Cn+1H2), the absorption peaks intensity increased when the polyynes were produced at different laser energies and the formation rats of polyynes increased with the increasing of laser pulse number. The FTIR absorption peak at 2368.4 cm-1, 1640.0 cm-1 and 1276.8 cm-1 stretching vibration bond, were refer to the C ≡ C, C = C and C-C, respectively. A bond suggests the formation carbon nanoparticles suspend in this solvent and the TEM show the formation of spherical nanoparticles with size ranges from (1.2 to 105.9 nm) and aggregation of the carbon nanoparticles.

Microwave assisted synthesis and antimicrobial activity of Fe3O4-doped ZrO2 nanoparticles

Composites play important role in dental filling by controlling shrinkage along with correction in teeth's shape and position. Rehabilitation of severely worn dentition can be achieved using mechanically strong composites. This study aims to synthesize zirconia-based composites to be used as dental fillers. Effect of microwave powers (100–900 W) along with Fe3O4 doping are studied on the structural, mechanical and magnetic properties of stabilized zirconia. SEM and TEM reveal formation of spherical nanoparticles with diameter of ∼30 nm. XRD results shows phase pure tetragonal zirconia (t-ZrO2) at microwave power of 500 W without any post heat treatment. Crystallite size calculated from XRD data (∼23 nm) matches well with the previously reported value for stabilization of t-ZrO2. Microwave energy dissipation results in stresses causing volume shrinkage leading to monoclinic to tetragonal phase transformation with higher X-ray density and hardness of ∼1347HV. VSM results show ferromagnetic response with low coercivity (600Oe) value and saturation magnetization (∼2emu/g). It is worth mentioning here that this is one of its kind study reporting synthesis of room temperature stabilized Fe3O4 doped zirconia composites at microwave power of 500 W. Antibacterial studies reveal inhibition zone of ∼32 mm against bacillus bacteria suggesting their potential use as dental filler.

Development of highly stable colloidal dispersions of gelled-oil nanoparticles loaded with cuminaldehyde

The main objective of this work was to develop an aqueous dispersion of gelled-oil nanoparticles as a novel carrier for cuminaldehyde. A hot emulsification process followed by cooling to room temperature was used to prepare gelled-oil nanoparticles in the presence of monoglyceride as organogelator. The effects of monoglyceride (10% and 15% w/w of the total lipid phase) and cuminaldehyde (0, 500 and 1000 mg/L) concentrations on different characteristics (e.g. droplet size, zeta potential, physical stability, rheology, encapsulation efficiency, release behavior and morphology) of the colloidal dispersions were studied during 28-d storage. The average droplet size of freshly prepared samples was within the range of 117–138 nm with a relatively narrow distribution. Large negative ζ-potential values (−38 to −55 mV) were a proof for the kinetic stability of the colloidal dispersions. Samples which were prepared with 10% monoglyceride showed a higher physical stability over a period of 90 d. Non-Newtonian (shear-thinning) and solid-like viscoelastic properties were observed due to particle-particle interactions. The results of the temperature ramp test confirmed that the droplets were in the gelled state. An increase in the organogelator concentration decreased the interfacial tension and contact angle. Transmission electron microscopy micrographs confirmed the formation of spherical nanoparticles. The encapsulation efficiency of cuminaldehyde in gelled-oil nanoparticles was 73–87%. In-vitro release profiles exhibited that the release of cuminaldehyde from gelled-oil nanoparticles in the simulated gastric fluid was lower than its release in the simulated intestinal fluid. Moreover, the release was increased by decreasing the concentration of organogelator. The obtained colloidal dispersions have the potential to be utilized as effective encapsulation systems for poorly water-soluble nutraceuticals.

Enhanced cytotoxic activity of curcumin on cancer cell lines by incorporating into gold/chitosan nanogels

Abstract The present research reports the successful synthesis of curcumin loaded core–shell nanostructures composed of gold nanoparticles and chitosan. Gold nanoparticles were obtained by reducing AuCl4− in the presence of tripolyphosphate (TPP) and chitosan. The prepared gold/chitosan (gold/CS) nanogels were characterized by UV-Vis spectroscopy. The particle size of the gold/CS core-shell nanogels was determined by DLS to be 36.85 ± 3.21 nm and the XRD analysis confirmed the crystal structure of gold. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) both confirmed the formation of spherical nanoparticles with the average particle size of about 35 nm. The results revealed drug loading and encapsulating efficiency for curcumin to be 11 ± 3.55% and 78.66 ± 3.05%, respectively. The drug release profile of nanocarrier was studied both in acidic and neutral buffered solutions (pH values of 5.3 and 7.4) and the results showed that the nanocarrier responded dramatically to acidic pH. Fluorescent images proved the successful internalization of the gold/CS nanostructures into Huh7 and MCF7 cells. The data from cell viability assays also demonstrated much better cytotoxic effects of the curcumin-loaded nanogels compared to free curcumin on both MCF7 and Huh7 cell lines. According to our findings, the gold/CS nanostructures can be presented to further investigations in order to find out new solutions to improve therapeutic efficiency of curcumin.

Comparing toxicity and bioactivity of gold nanoparticles synthetized using two brown algae Cystoseira sp

Event Abstract Back to Event Comparing toxicity and bioactivity of gold nanoparticles synthetized using two brown algae Cystoseira sp Sofia Machado1, Anabela Gonçalves1, Noelia González-Ballesteros2, Luana Magalhães1, Marisa P. Sárria3, Maria Carmen Rodríguez-Argüelles2* and Andreia C C. Gomes1, 4* 1 Centre of Molecular and Environmental Biology, Department of Biology, University of Minho, Portugal 2 Department of Inorganic Chemistry, University of Vigo, Spain 3 Laboratório Ibérico Internacional de Nanotecnologia (INL), Portugal 4 Institute of Science and Innovation for Bio-Sustainability, University of Minho, Portugal The marine ecosystem has captured a major attention in recent years since various biologically active compounds have been isolated and screened for pharmacological activity from dissimilar marine provenience. Marine biological resources can be considered an essential for nanotechnology, researchers had been interested to synthesize metallic nanoparticles from marine source because it is thought to be ecofriendly, nontoxic, environmentally acceptable ‘‘green procedures”, reduces the down-streaming process making it very cost effective and the availableness of the source from the diverse marine ecosystem becomes a much easier task. The biosynthesized nanoparticles from marine compound offer stabilized nanoparticles through compounds present in the marine source that make them more efficient for both biomedical and industrial applications[1]. In this regard, we have focus our attention in two algae of Cystoseira. It is a genus of marine brown macroalgae composed of about 40 species. It is widely distributed in the North East Atlantic, the Baltic Sea and the Mediterranean. This genus contains a wide variety of secondary metabolites (e.g. terpenoids, steroids, phlorotannins, phenolic compounds, carbohydrates, triacylglycerols/fatty acids, pigments, vitamins) that are associated with pharmacological properties, such as antioxidant, anti-inflammatory, cytotoxicity, anticancer, cholinesterase inhibition and anti-diabetic activities but also antibacterial, antifungal and anti-parasitic activities [2]. Cystoseira baccata (CB) and Cystoseira tamariscifolia (CT) are two species of this genus that differ in geographic distribution, morphology and possibly content of secondary metabolites. Gold nanoparticles are presently under intensive study since they can be the remarkable scaffold for novel biological and chemical applications owing to their unique electrical, chemical and optical properties. Such as their easy synthesis and good biocompatibility due to the low reactivity of the golden core. Therefore presenting potential applications in the development of new technologies in different fields such as in the food, cosmetic and pharmaceutical industry [3,4]. Previously, González-Ballesteros et al have reported the synthesis of gold nanoparticles with antitumor activity led by the macroalga CB [5]. In the present study, we have compared the ability of C. baccata and C. tamariscifolia (CT) in the synthesis of gold nanoparticles. With this aim, aqueous extracts of the two macroalgae were prepared and their reducing activity, total phenolic content and DPPH scavenging activity were determined before and after the synthesis of nanoparticles. Results showed that CT possess three times more reducing power, almost 4 times more phenolic content and 4 time more DPPH scavenging activity than CB. The nanoparticles obtained were characterized by UV-Vis spectroscopy and Transmission electron microscopy confirming the formation of spherical nanoparticles with a mean diameter of 8.4 ± 2.2 nm in the case of Au@CB and 7.6 ± 2.2 nm for Au@CT. In order to compare the biological potential of both CT and CB extracts and their respective gold nanoparticles (Au@CT and Au@CB), it was investigated whether they affect the viability in mouse (L929 cell line) and human (BJ5-ta cell line) fibroblast cells as in vitro models, by evaluating cellular metabolism by tetrazolium-based colorimetric cellular assay (MTT); cell membrane integrity by lactate dehydrogenase activity (LDH); wound-healing assay to asses effects on cell proliferation and migration capacity. Both algae extracts and derived nanoparticles present a non-cytotoxic profile in lower concentrations, which are efficient in cell regeneration, although with some differences between both species. For a correlation between in vitro and in vivo toxicity, the zebrafish embryo toxicity (ZET) assay, recomended by OECD to evaluate acute and chronic toxicity, was performed. This model organism has a translucent body, allowing real time observation, and allows the evaluation of whole organism responses, from mortality to more specific parameters such as neurotoxicity. The results show that toxicity is evident only at very high concentrations. These promising results thus support that green synthesis in CB and CT extracts of non-toxic, bioactive nanoparticles have an interesting potential for biomedical applications. Acknowledgements This work was supported by the strategic programme UID/BIA/04050/2019 funded by national funds through the Fundação para a Ciência e a Tecnologia I.P. (FCT, IP), FUN2CYT (POCI-01-0145-FEDER-030568) supported by Programa Operacional Competitividade e Internacionalização (FEDER) and FCT, IP. This work was also supported by the Xunta de Galicia ED431C 2018/54-GRC. NGB acknowledges a fellowship from Universidade de Vigo.