scholarly journals Synthesis of Gold Functionalised Nanoparticles with the Eranthis hyemalis Lectin and Preliminary Toxicological Studies on Caenorhabditis elegans

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1363 ◽  
Author(s):  
Jamila Djafari ◽  
Marie T. McConnell ◽  
Hugo M. Santos ◽  
José Luis Capelo ◽  
Emilia Bertolo ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Caenorhabditis Elegans ◽  
Biological Effect ◽  
Target Cells ◽  
Type Ii ◽  
Obvious Effect ◽  
Transmission Electron ◽  
Toxicological Studies ◽  
Vis Spectroscopy ◽  
Free Living Nematode

The lectin found in the tubers of the Winter Aconite (Eranthis hyemalis) plant (EHL) is a Type II Ribosome Inactivating Protein (RIP). Type II RIPs have shown anti-cancer properties and have great potential as therapeutic agents. Similarly, colloidal gold nanoparticles are successfully used in biomedical applications as they can be functionalised with ligands with high affinity and specificity for target cells to create therapeutic and imaging agents. Here we present the synthesis and characterization of gold nanoparticles conjugated with EHL and the results of a set of initial assays to establish whether the biological effect of EHL is altered by the conjugation. Gold nanoparticles functionalised with EHL (AuNPs@EHL) were successfully synthesised by bioconjugation with citrate gold nanoparticles (AuNPs@Citrate). The conjugates were analysed by UV-Vis spectroscopy, Dynamic Light Scattering (DLS), Zeta Potential analysis, and Transmission Electron Microscopy (TEM). Results indicate that an optimal functionalisation was achieved with the addition of 100 µL of EHL (concentration 1090 ± 40 µg/mL) over 5 mL of AuNPs (concentration [Au0] = 0.8 mM). Biological assays on the effect of AuNPs@EHL were undertaken on Caenorhabditis elegans, a free-living nematode commonly used for toxicological studies, that has previously been shown to be strongly affected by EHL. Citrate gold nanoparticles did not have any obvious effect on the nematodes. For first larval stage (L1) nematodes, AuNPs@EHL showed a lower biological effect than EHL. For L4 stage, pre-adult nematodes, both EHL alone and AuNPs@EHL delayed the onset of reproduction and reduced fecundity. These assays indicate that EHL can be conjugated to gold nanoparticles and retain elements of biocidal activity.

scholarly journals Synthesis of Gold Functionalised Nanoparticles with the Eranthis hyemalis Lectin and Preliminary Toxicological Studies on Caenorhabditis elegans

2018 ◽  
Author(s):  
Jamila Djafari ◽  
Marie T. McConnell ◽  
Hugo M. Santos ◽  
José Luis Capelo ◽  
Emilia Bertolo ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Caenorhabditis Elegans ◽  
Biological Effect ◽  
Life Stage ◽  
Target Cells ◽  
Type Ii ◽  
Biological Assays ◽  
C Elegans ◽  
Toxicological Studies ◽  
Vis Spectroscopy

The lectin found in the tubers of the Winter Aconite (Eranthis hyemalis) plant (EHL) is a Type II Ribosome Inactivating Protein (RIP); type II RIPs have shown anti-cancer properties, and have great potential as therapeutic agents. Similarly, colloidal gold nanoparticles are successfully used in biomedical applications as gold nanoparticles can be functionalised with ligands with high affinity and specificity for target cells to create therapeutic and imaging agents. Herein we present the synthesis and characterization of gold nanoparticles conjugated with EHL. The aim was to establish the viability of the conjugate and perform a set of initial assays to establish whether the biological effect of EHL is altered by the conjugation. The biological assays were performed in Caenorhabditis elegans, a free living nematode commonly used for toxicological studies; previous work from some of the authors using first life stage (L1) nematodes has shown that EHL has a strong biocidal effect on C. elegans. Gold nanoparticles functionalised with EHL (AuNPs@EHL) were successfully synthesised by bioconjugation with citrate gold nanoparticles (AuNPs@Citrate); the conjugates were analysed by UV-Vis spectroscopy, Dynamic Light Scattering (DLS), Zeta Potential analysis and Transmission Electron Microscopy (TEM). Results indicate that an optimal functionalisation was achieved with the addition of 100 µL of EHL (concentration 1090 ± 40 µg/mL) over 5 mL of AuNPs (concentration [Au0] = 0.8 mM). Biological assays on the effect of AuNPs@EHL on C. elegans were performed, using first life stage (L1) and pre-adult stage (L4) nematodes. Citrate gold nanoparticles did not have any obvious effect on the nematodes. For L1 stage nematodes, the assays show that conjugation with gold nanoparticles reduced the biological effect of EHL on C. elegans. As lectin binding activity is essential for the natural protein to bind and allow entry to cells, conformational changes due to conjugation may have affected this binding affinity. For L4 stage nematodes, both EHL alone and AuNPs@EHL showed biological activity, and reproductive delays and reduced fecundity were observed in both cases. These assays indicate that EHL can be conjugated to gold nanoparticles and retain elements of biocidal activity.

scholarly journals Effects of Different Surfactant Charges on the Formation of Gold Nanoparticles by the LASiS Method

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2937
Author(s):  
Muhammad Zulfajri ◽  
Wei-Jie Huang ◽  
Genin-Gary Huang ◽  
Hui-Fen Chen
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Gold Nanoparticles ◽  
Laser System ◽  
Synthesis Process ◽  
Au Nps ◽  
Laser Fluences ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
532 Nm

The laser ablation synthesis in solution (LASiS) method has been widely utilized due to its significant prospects in laser microprocessing of nanomaterials. In this study, the LASiS method with the addition of different surfactant charges (cationic CTAB, nonionic TX-100, and anionic SDS) was used to produce Au NPs. An Nd:YAG laser system at 532 nm excitation with some synthetic parameters, including different laser fluences, ablation times, and surfactant concentrations was performed. The obtained Au NPs were characterized by UV-Vis spectroscopy, transmission electron microscopy, and zeta potential analyzer. The Au NPs exhibited the maximum absorption peak at around 520 nm for all samples. The color of Au NPs was changed from red to reddish by increasing the laser fluence. The surfactant charges also played different roles in the Au NPs’ growth during the synthesis process. The average sizes of Au NPs were found to be 8.5 nm, 5.5 nm, and 15.5 nm with the medium containing CTAB, TX-100, and SDS, respectively. Besides, the different surfactant charges induced different performances to protect Au NPs from agglomeration. Overall, the SDS and CTAB surfactants exhibited higher stability of the Au NPs compared to the Au NPs with TX-100 surfactant.

scholarly journals Aggregation of Gold Nanoparticles in Presence of the Thermoresponsive Cationic Diblock Copolymer PNIPAAM48-b-PAMPTMA6

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4066
Author(s):  
David Herrera Robalino ◽  
María del Mar Durán del Amor ◽  
Carmen María Almagro Gómez ◽  
José Ginés Hernández Cifre
Keyword(s):  
Gold Nanoparticles ◽  
High Ionic Strength ◽  
Solution Temperature ◽  
Trimethylammonium Chloride ◽  
Aggregation Process ◽  
Critical Solution Temperature ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Copolymer Poly ◽  
Positively Charged

The adsorption of the thermoresponsive positively charged copolymer poly(N-isopropylacrylamide)-block-poly(3-acrylamidopropyl)trimethylammonium chloride, PNIPAAM48-b-PAMPTMA6(+), onto negatively charged gold nanoparticles can provide stability to the nanoparticles and make the emerging structure tunable by temperature. In this work, we characterize the nanocomposite formed by gold nanoparticles and copolymer chains and study the influence of the copolymer on the expected aggregation process that undergoes those nanoparticles at high ionic strength. We also determine the lower critical solution temperature (LCST) of the copolymer (around 42 °C) and evaluate the influence of the temperature on the nanocomposite. For those purposes, we use dynamic light scattering, UV-vis spectroscopy and transmission electron microscopy. At the working PNIPAAM48-b-PAMPTMA6(+) concentration, we observe the existence of copolymer structures that trap the gold nanoparticles and avoid the formation of nanoparticles aggregates. Finally, we discuss how these structures can be useful in catalysis and nanoparticles recovery.

scholarly journals Biosynthesized gold nanoparticles-doped hydroxyapatite as antibacterial and antioxidant nanocomposite

2021 ◽  
Author(s):  
Is Fatimah ◽  
Putwi Widya Citradewi ◽  
Amri Yahya ◽  
Bambang Nugroho ◽  
Habibi Hidayat ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Antioxidant Activity ◽  
Particle Size ◽  
Gold Nanoparticles ◽  
Antibacterial Activity ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Dpph Scavenging Activity ◽  
Dpph Scavenging

Abstract The composite of green synthesized gold nanoparticles (Au NPs)-doped hydroxyapatite (HA) has been prepared. The gold nanoparticles were produced via bioreduction of HAuCl4 with Clitoria ternatea flower extract, and utilized in the synthesis of hydroxyapatite using Ca(OH)2 and ammonium diphosphate as precursor. The aim of this research is to study the structural analysis of the composite and antibacterial activity test toward Eschericia coli, Staphylococcus aureus, Klebsiela pneumoniae, and Streptococcus pyogenes. In addition, the antioxidant activity was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging method. The monitoring of gold nanoparticles formation was conducted by UV–vis spectroscopy and particle size analyses, meanwhile the synthesized composite was studied using X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The results showed that homogeneously dispersed gold nanoparticles in HA structure was obtained with the particle size ranging at 5-80 nm. The nanocomposite demonstrated antibacterial activity against tested bacteria. The nanocomposite expressed an antioxidant activity as shown by the DPPH scavenging activity of 66 and 58% at the concentration of 100 μg/mL and 50 μg/mL, respectively.

scholarly journals Exploration of the Antimicrobial and Catalytic Properties of Gold Nanoparticles Greenly Synthesized by Cryptolepis buchanani Roem. and Schult Extract

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Kamonpan Wongyai ◽  
Phitchayapak Wintachai ◽  
Rasimate Maungchang ◽  
Parawee Rattanakit
Keyword(s):  
Staphylococcus Aureus ◽  
Gold Nanoparticles ◽  
Analytical Techniques ◽  
Average Diameter ◽  
Face Centered Cubic ◽  
Tem Analysis ◽  
X Ray ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Face Centered

A green, simple, and rapid synthesis of gold nanoparticles using plant extract, Cryptolepis buchanani Roem. and Schult, and their applications are first described in this paper. The formation of gold nanoparticles was visually observed by the appearance of a ruby red color, which was further indicated by an absorption peak at 530 nm in UV-Vis spectroscopy. Optimization of reaction parameters for the gold nanoparticles was also investigated. Various analytical techniques were employed as part of the process of characterizing the resulting gold nanoparticles. Fourier transform infrared (FTIR) analysis revealed that the phenol compounds present in the extract were responsible for gold(III) reduction and stabilization of gold nanoparticles. Transmission electron microscopy (TEM) analysis showed that the gold nanoparticles were spherical in shape with an average diameter of 11 nm. Powder X-ray diffraction (XRD) pattern indicated that the green synthesis approach produced highly crystalline, face-centered cubic gold nanoparticles. Energy-dispersive X-ray spectroscopy (EDS) measurements confirmed the presence of elemental gold in the prepared nanoparticles. The negative zeta potential value of gold nanoparticles was found to be -30.28 mV. The green synthesized gold nanoparticles expressed effective antibacterial activity against Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, and Acinetobacter baumannii and exhibited an excellent catalytic property in terms of its reduction ability of methylene blue.

scholarly journals Electrospinning Synthesis and Photocatalytic Activity of Mesoporous TiO2Nanofibers

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Jing Li ◽  
Hui Qiao ◽  
Yuanzhi Du ◽  
Chen Chen ◽  
Xiaolin Li ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
High Photocatalytic Activity ◽  
Electrospinning Technique ◽  
Obvious Effect ◽  
Simple Method ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Excellent Photocatalytic Activity

Titanium dioxide (TiO2) nanofibers in the anatase structure were successfully prepared via electrospinning technique followed by calcination process. The morphologies, crystal structure, surface area, and the photocatalytic activity of resulting TiO2nanofibers were characterized by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), nitrogen sorption, and UV-vis spectroscopy. The results revealed that calcination temperature had greatly influenced the morphologies of TiO2nanofibers, but no obvious effect was noticed on the crystal structure of TiO2nanofibers. The photocatalytic properties of TiO2nanofibers were evaluated by photocatalytic degradation of rhodamine B (RhB) in water under visible light irradiation. It was observed that TiO2nanofibers obtained by calcination at 500°C for 3 hours exhibited the most excellent photocatalytic activity. We present a novel and simple method to fabricate TiO2nanofibers with high-photocatalytic activity.

scholarly journals Synthesis of Gold Nanoparticles and Association of DNA-Gold Nanoparticles

2016 ◽  
Vol 11 (2) ◽  
pp. 77
Author(s):  
Weon Bae Ko ◽  
Young Min Lee ◽  
Sung Kyu Hong ◽  
Sung Sook Choi ◽  
Sang Jin Lee
Keyword(s):  
Electron Microscopy ◽  
Gold Nanoparticles ◽  
Gel Electrophoresis ◽  
Bos Taurus ◽  
Ionic Surfactant ◽  
Polysorbate 80 ◽  
Specific Primer ◽  
Binding Ability ◽  
Transmission Electron ◽  
Vis Spectroscopy

<p>This study examined the synthesis of gold nanoparticles using a non-ionic surfactant, polysorbate 80, and KAuCl<sub>4 </sub>in water. The gold nanoparticles, which were well dispersed in water, were analyzed by UV-vis spectroscopy and transmission electron microscopy (TEM). In addition, the SRY(sex-determining region Y) gene of the Bos taurus specific primer was designed, and this primer solution was mixed with the aqueous gold nanoparticles solution. The binding ability of DNA and gold nanoparticles was identified by polyacryllamide gel electrophoresis. The products of DNA linked with gold nanoparticles were also characterized by UV-vis spectroscopy and TEM.</p>

scholarly journals Plasmonic Sensing of Aqueous-Divalent Metal Ions by Biogenic Gold Nanoparticles

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Luisa E. Silva-De Hoyos ◽  
Victor Sánchez-Mendieta ◽  
Alfredo R. Vilchis-Nestor ◽  
Miguel A. Camacho-López ◽  
Jésica Trujillo-Reyes ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Aqueous Solutions ◽  
Metal Ions ◽  
Plasmon Resonance ◽  
Chemical Interaction ◽  
Divalent Metal ◽  
Divalent Metal Ions ◽  
Colloidal Solutions ◽  
Transmission Electron ◽  
Vis Spectroscopy

The chemical interaction between biogenic gold nanoparticles (AuNPs) and several metal (II) ions can be regarded as a practical, twofold, colorimetric, and plasmon resonance sensing method for the recognition of some divalent metal ions in aqueous solutions. The green synthesized AuNPs, using Camellia sinensis as a reducing agent, were characterized by a surface plasmon resonance (SPR) using UV-Vis spectroscopy, infrared spectroscopy, and transmission electron microscopy. The AuNP colloidal solutions obtained have a pink-reddish color with SPRs centered between 529 and 536 nm. AuNPs with spherical, triangular, and hexagonal shapes were found by TEM analyses. Despite their divergent morphologies, these AuNPs can be employed as colorimetric and plasmon resonance sensors for detection of Ca2+, Sr2+, Cu2+, and Zn2+, primarily, in aqueous solutions. Sensibility studies based on molar concentrations were also performed for these metal ions. Furthermore, solid biogenic AuNPs/cellulosic biocomposites were prepared with the aim of developing portable, fast, and dependable colorimetric sensors; nevertheless, these biocomposites resulted to be good adsorbent materials of metal ions.

SERS properties of biogenic gold nanoparticles synthesized using Anemopsis californica extract.

MRS Advances ◽  
2020 ◽  
Vol 5 (63) ◽  
pp. 3397-3406
Author(s):  
R. D. Ávila-Avilés ◽  
Marco A. Camacho-López ◽  
E. Castro-Longoria ◽  
A. Dorazco-González ◽  
N. Hernández-Guerrero ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Raman Signal ◽  
Sers Substrate ◽  
Anemopsis Californica ◽  
Glass Slides ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering ◽  
Biological Methods

AbstractGold nanoparticles (AuNPs) have been classified as one of the most attractive nanotechnologies, thanks to their potential or already implemented applications; therefore, biological methods for their synthesis have been widely investigated. This study explores the synthesis of AuNPs using the extract of Anemopsis californica, and determinates the effect of the solvent used (water, methanol, and isopropanol) to obtain the AuNPs. Biogenic nanoparticles were analysed through UV-Vis spectroscopy and transmission electron microscopy (TEM, HRTEM, and SAED). Significant differences in polydispersity and morphology of AuNPs among the different methods used were found; the aqueous extract and the extract based on methanol formed nanotriangles and polyhedral nanoparticles; the shape of the nanoparticles is predominantly polyhedral when isopropanol is used as the solvent. The as obtained nanoparticles were placed on glass slides to perform Surface-Enhanced Raman Scattering (SERS) experiments, an amplification of the methylene blue Raman signal was observed when triangular nanoparticles cover the biogenic SERS substrate.

scholarly journals Role of Surfactant in the Formation of Gold Nanoparticles in Aqueous Medium

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Abhishek Das ◽  
Ridhima Chadha ◽  
Nandita Maiti ◽  
Sudhir Kapoor
Keyword(s):  
Gold Nanoparticles ◽  
Aqueous Medium ◽  
Sodium Dodecyl ◽  
Chloroauric Acid ◽  
Synthesis Mechanism ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
The Stability ◽  
Mediated Reduction

The stability of gold nanoparticles is a major issue which decides their impending usage in nanobiotechnological applications. Often biomimetically synthesized nanoparticles are deemed useless owing to their instability in aqueous medium. So, surfactants are used to stabilize the nanoparticles. But does the surfactant only stabilize by being adsorbed to the surface of the nanoparticles and not play significantly in moulding the size and shape of the nanoparticles? Keeping this idea in mind, gold nanoparticles (GNPs) synthesized by l-tryptophan (Trp) mediated reduction of chloroauric acid (HAuCl4) were stabilized by anionic surfactant, sodium dodecyl sulphate (SDS), and its effect on the moulding of size and properties of the GNPs was studied. Interestingly, unlike most of the gold nanoparticles synthesis mechanism showing saturation growth mechanism, inclusion of SDS in the reaction mixture for GNPs synthesis resulted in a bimodal mechanism which was studied by UV-Vis spectroscopy. The mechanism was further substantiated with transmission electron microscopy. Zeta potential of GNPs solutions was measured to corroborate stability observations recorded visually.

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