Tag: gold nanoparticles

Miquel Torras at the 3rd International Conference on Polyol Mediated Synthesis

25th-27th of June 2018

Miquel Torras, PhD student at the N&N group, travelled to Madrid to attend the 3rd International Conference on Polyol Mediated Synthesis (ICPMS) held at the Instituto de Ciencia de Materiales de Madrid (ICMM). Miquel presented the talk “Fast and Simple Microwave Synthesis of Multicomponent Gold Nanoparticles”.

Good job Miquel!

Hot off the press: First paper from Miquel and Pol!

Schematic representation of the two-step microwave-assisted synthesis of Au/TiO2 nanostructures.

New publication from the N&N group in collaboration with the Universitat Politècnica de Catalunya!


Congratulations to all the authors of the manuscript and especially to Miquel Torras (Ph.D. student at the N&N group) and Pol Sallés (previous researcher at the N&N group) for the first publication of their careers! The paper “Fast and Simple Microwave Synthesis of TiO2/Au Nanoparticles for Gas-Phase Photocatalytic Hydrogen Generation” has been published on April 12th 2018 at the open access journal Frontiers in Chemistry.


Abstract: The fabrication of small anatase titanium dioxide (TiO2) nanoparticles (NPs) attached to larger anisotropic gold (Au) morphologies by a very fast and simple two-step microwave-assisted synthesis is presented. The TiO2/Au NPs are synthesized using polyvinylpyrrolidone (PVP) as reducing, capping and stabilizing agent through a polyol approach. To optimize the contact between the titania and the gold and facilitate electron transfer, the PVP is removed by calcination at mild temperatures. The nanocatalysts activity is then evaluated in the photocatalytic production of hydrogen from water/ethanol mixtures in gas-phase at ambient temperature. A maximum value of 5.3 mmol·g−1cat⋅gcat-1·h−1 (7.4 mmol·g−1TiO2⋅gTiO2-1·h−1) of hydrogen is recorded for the system with larger gold particles at an optimum calcination temperature of 450°C. Herein we demonstrate that TiO2-based photocatalysts with high Au loading and large Au particle size (≈50 nm) NPs have photocatalytic activity.

Accepted paper in Acta Biomaterialia on testing gold nanoparticles in vivo using C. elegans

The paper In vivo testing of gold nanoparticles using the Caenorhabditis elegans model organism” has been publised in Acta Biomaterialia (Available online 1 February 2017; doi: 10.1016/j.actbio.2017.01.080). 

The authors of the paper are Laura González-Moragas, Pascal Berto, Clara VilchesRomain Quidant, Androniki Kolovou, Rachel Santarella-Mellwig, Yannick Schwab, Stephen Stürzenbaum, Anna Roig, and Anna Laromaine

The paper is a result of a collaboration between the NN Group at ICMAB (González-Moragas, Roig and Laromaine), the ICFO-Institut de Ciències Fotòniques (Berto, Vilches and Quidant), the European Molecular Biology Laboratory, EMBL in Heidelberg, Germany (Kolovou, Santarella-Mellwig, Schwab) and King’s College London in UK (Stürzenbaum).  



Gold nanoparticles (AuNPs) are present in many man-made products and cosmetics, and are also used by the food and medical industries. Tight regulations regarding the use of mammalian animals for product testing can hamper the study of the specific interactions between engineered nanoparticles and biological systems. Invertebrate models, such as the nematode Caenorhabditis elegans (C. elegans), can offer alternative approaches during the early phases of nanoparticle discovery.

Panels B and C are optical microscopy images of B) 11-nm and C) 150-nm AuNPs treated worms. 11-nm AuNPs appear pink, and 150-nm AuNPs appear blue.

Here, we thoroughly evaluated the biodistribution of 11-nm and 150-nm citrate-capped AuNPs in the model organism C. elegans at multiple scales, moving from micrometric to nanometric resolution and from the organism to cellular level. We confirmed that the nanoparticles were not able to cross the intestinal and dermal barriers. We investigated the effect of AuNPs on the survival and reproductive performance of C. elegans, and correlated these effects with the uptake of AuNPs in terms of their number, surface area, and metal mass. In general, exposure to 11-nm AuNPs resulted in a higher toxicity than the larger 150-nm AuNPs. NP aggregation inside C. elegans was determined using absorbance microspectroscopy, which allowed the plasmonic properties of AuNPs to be correlated with their confinement inside the intestinal lumen, where anatomical traits, acidic pH and the presence of biomolecules play an essential role on NP aggregation. Finally, quantitative PCR of selected molecular markers indicated that exposure to AuNPs did not significantly affect endocytosis and intestinal barrier integrity.


Laura González will defend her Doctoral Thesis on Friday, December 16th at 12 pm at ICMAB

This Friday 16th of December Laura González is going to defend her Doctoral Thesis entitled “Evaluating inorganic nanoparticles in the living organism Caenorhabditis elegans”, supervised by Dr. Anna Laromaine and Dr. Anna Roig

In this thesis, we have used the simple model organism Caenorhabditis elegans as an in vivo biological system to screen inorganic nanoparticles (NPs) with biomedical uses. In particular, we have assessed the behaviour of two types of particles with different composition, size and surface properties: iron oxide NPs coated with citrate and bovine serum albumin, and gold nanoparticles of two different sizes. We have studied their interactions with C. elegans including their uptake, fate, biological effects and NP-responsive molecular mechanisms, and compared our results with previous studies. To this end, we have combined toxicity tests, materials science and imaging techniques and gene expression analysis. We have been able to perform this biological evaluation in the synthetic laboratory where the particles were synthesized and characterised due to the advantageous experiments features of C. elegans.In summary, this thesis exploits the potential of C. elegans as a simple animal model to evaluate NPs in the initial stages of development and contributes to: (i) a systematic and comprehensive evaluation of NPs in C. elegans, in particular studying the influence of NP properties (size, surface coating and core composition) on their in vivo effects, (ii) extend the toolkit of techniques available to characterise nano-bio interactions in small organisms.

The Jury Members will be:

Everyone is invited to join the presentation, that will be held at 12 pm at ICMAB Conference Room Carles Miravitlles. After the defense, there will be a “pica-pica” for everyone in the dining room. 

Miquel Torras is back with us to do his MSc Thesis in magnetic plasmonic nanotriangles

Miquel Torras in the labMiquel Torras, who was in the N&N Group during last semester to do his Degree’s Final Project, is back with us this year. He has started a MSc in Applied Materials Chemistry at Universitat de Barcelona (UB) and will do his MSc Thesis in the group, under the supervision of Anna Roig. He will be working on the synthesis and characterization of magnetic and plasmonic gold nanotriangles

Welcome back!

Jordi Llorca, one of our collaborators from INTE-UPC, in the Catalan newspaper ara.cat, talks about photocatalysis

Ciència.cat from ara.catJordi Llorca, from Institut de Tècniques Energètiques (INTE-UPC) explains in this video from the newspaper ara, one of the projects in which we collaborate: photocatalysis for hydrogen production from sunlight, a photocatalyst formed by TiO2/Au nanoparticles, and water: 

The video is part of the article, in Catalan: Com produïm electricitat amb el sol i l’hidrogen? 

In the video he says: “We obtain hydrogen -which is not in its free state in the Earth- to act as a source of energy, and to obtain it, we use use sunlight -completely clean-, a photocatalyst containing nanoparticles, and water.”

This article is part of a special issue called Ciència.cat about research and science in Catalunya, appeared this last Sunday with the newspaper ara.

You can find the special issue here: Ciència.cat

Hot off the press: accepted manuscript in Chem. Commun.


Today is the big day: second manuscript accepted!

The manuscript “A silica-based magnetic platform decorated with mixed ligand gold nanoparticles: A recyclable catalyst for esterification reactions” (Elif Ertem, Nerea Murillo-Cremaes, Randy Patrick Carney, Anna Laromaine, Emma-Rose Janeček, Anna Roig* and Francesco Stellaccia*; DOI: 10.1039/C6CC01146B) has been accepted in Chemical Communications

This paper describes a novel and convenient synthetic strategy for the preparation of magnetically responsive silica nanospheres decorated with mixed ligand protected gold nanoparticles. Gold nanoparticles are attached to the silica surface via stable amide bond formation. The hierarchical nanospheres show promising results as a reusable and efficient catalyst for esterification reactions and they can be recovered through a simple magnetic separation.


Figure: Schematic illustration of: (a) the partial ligand exchange of 3-mercapto-1-propanesulfonate (MPSA):1-octanethiol(OT) covered gold nanoparticles, (b) the synthesis of core-shell magnetic silica and (c) the synthesis of the magnetic silica decorated with gold nanoparticles hierarchical nanospheres.

Hot off the press: accepted manuscript in Faraday Discussions!

FARADAY_Forthcoming-publcation-198x300We are very happy to announce that the manuscript Gold nanotriangles decorated with superparamagnetic iron oxide nanoparticles: a compositional and microstructural study (J.A. Hachtela, S. Yuc , A.R. Lupini, S.T. Pantelidesa, M. Gich, A. Laromaine, A. Roig, DOI: 10.1039/C6FD00028B) has been accepted by the Faraday Discussions journal.

The manuscript will be presented and discussed at a forthcoming Faraday Discussions meeting, this next summer. During the meeting, all delegates will be able to contribute to the debate, which will be included in the final volume. This will be a great opportunity to discuss the formation mechanism of the magnetic gold nanotriangles with some experts on this field. 

The combination of iron oxide and gold in a single nanoparticle results in both magnetic and plasmonic properties that can stimulate novel applications in bio-sensing, medical imaging, or therapeutics. Microwave heating method allows the fabrication of multi-component, multi-functional nanostructures by promoting selective heating at desired sites. Recently, we reported a microwave-assisted polyol route yielding gold nanotriangles decorated with iron oxide nanoparticles (1). Here, we present an in-depth microstructural and compositional characterization of the system by using scanning transmission electron microscopy (STEM) and electron energy loss (EELS) spectroscopy. A method to remove the iron oxide nanoparticles from the gold nanocrystals and some insights on crystal nucleation and growth mechanisms are also provided.


Figure: (a) Schematic representation of the synthesis route. (b) HRTEM image of a Au NH-SPIONs and a Au NT-SPIONs. Characterization of the heterostructures: (c) UV-Vis-NIR spectra. (d) Hydrodynamic diameter of the Au-SPIONS measured by DLS. (e) Magnetization curve up to 6 T at 5K.

(1) Magnetic gold nanotriangles by microwave polyol synthesis (S.M. Yu, J.A. Hachtel, M.F. Chisholm, S.T. Pantelides, A. Laromaine, A. Roig; Nanoscale 2015, 7, 14039-14046. DOI: 10.1039/C5NR03113C).