Staff directory

Neus Gómez Bastus

Senior Researcher
Inorganic Nanoparticles



  • Modeling the Optical Responses of Noble Metal Nanoparticles Subjected to Physicochemical Transformations in Physiological Environments: Aggregation, Dissolution and Oxidation

    Piella J., Bastús N.G., Puntes V. Zeitschrift fur Physikalische Chemie; 231 (1): 33 - 50. 2017. 10.1515/zpch-2016-0874.

    Herein, we study how optical properties of colloidal dispersions of noble metal nanoparticles (Au and Ag) are affected by processes such as aggregation and oxidative dissolution. The optical contributions of these processes to the extinction spectra in the UV-vis region are often overlapped, making difficult its interpretation. In this regard, modeling the UV-vis spectra (in particular absorbance curve, peaks position, intensity and full width at half maximum-FWHM) of each process separately offers a powerful tool to identify the transformation of NPs under relevant and complex scenarios, such as in biological media. The proper identification of these transformations is crucial to understand the biological effects of the NPs. © 2017 Walter de Gruyter GmbH, Berlin/Boston.

  • One-Pot Synthesis of Cationic Gold Nanoparticles by Differential Reduction

    Sperling R.A., Garciá-Fernández L., Ojea-Jiménez I., Piella J., Bastús N.G., Puntes V. Zeitschrift fur Physikalische Chemie; 231 (1): 7 - 18. 2017. 10.1515/zpch-2016-0864.

    The size-controlled synthesis of cationic particles by differential reduction of HAuCl4 precursor in the presence of NaBH4 and 1-aminoundecane-12-thiol (AUT) is reported. The number of seed particles is determined by the fraction of the initially Au precursor reduced by NaBH4 present in the reaction mixture, which are then grown larger by the AUT, acting as both weak reducing agent and stabilizing surfactant. By this methodology, size controlled synthesis is achieved in a two-step one-pot synthesis at room temperature. © 2017 Walter de Gruyter GmbH, Berlin/Boston.


  • One-pot polyol synthesis of highly monodisperse short green silver nanorods

    Patarroyo J., Genç A., Arbiol J., Bastús N.G., Puntes V. Chemical Communications; 52 (73): 10960 - 10963. 2016. 10.1039/c6cc04796c. IF: 6.567

    Green silver nanorods (Ag NRs) of a low aspect ratio (2.8) have been produced in high yields via an optimized, simple, and robust one-pot polyol method in the presence of tannic acid, which favors the nucleation of decahedral seeds needed for the production of monodisperse Ag NRs. These Ag NRs were further used as sacrificial templates to produce Au hollow nanostructures via galvanic replacement reaction with HAuCl4 at room temperature. © 2016 The Royal Society of Chemistry.

  • Quantifying the Sensitivity of Multipolar (Dipolar, Quadrupolar, and Octapolar) Surface Plasmon Resonances in Silver Nanoparticles: The Effect of Size, Composition, and Surface Coating

    Bastús N.G., Piella J., Puntes V. Langmuir; 32 (1): 290 - 300. 2016. 10.1021/acs.langmuir.5b03859. IF: 3.993

    The effect of composition, size, and surface coating on the sensitivity of localized multipolar surface plasmon resonances has been spectroscopically investigated in high-quality silver colloidal solutions with precisely controlled sizes from 10 to 220 nm and well-defined surface chemistry. Surface plasmon resonance modes have been intensively characterized, identifying the size-dependence of dipolar, quadrupolar, and octapolar modes. Modifications of the NP's surface chemistry revealed the higher sensitivity of large sizes, long molecules, thiol groups, and low-order resonance modes. We also extend this study to gold nanoparticles, aiming to compare the sensitivity of both materials, quantifying the higher sensitivity of silver. © 2015 American Chemical Society.

  • Shell or Dots - Precursor Controlled Morphology of Au-Se Deposits on CdSe Nanoparticles

    De La Cueva L., Meyns M., Bastús N.G., Rodríguez-Fernández J., Otero R., Gallego J.M., Alonso C., Klinke C., Juárez B.H. Chemistry of Materials; 28 (8): 2704 - 2714. 2016. 10.1021/acs.chemmater.6b00287. IF: 9.407

    The most prevalent image of the morphology of Au-CdSe hybrid nanoparticles (HNPs) is that of dumbbells or matchsticks with CdSe nanoparticles (NPs) acting as seed material onto which spherical Au dots are deposited. On the basis of a system with only three reaction components, CdSe seeds, n-dodecyltrimethylammonium bromide-complexed AuCl3, and dodecanethiol, we demonstrate how the morphology of the Au deposits on the semiconductor NPs, either in the form of dots on the vertices or in the form of a shell around the NP surface, can be determined by controlling the oxidation state of the metal precursor. Furthermore, we apply X-ray photoelectron spectroscopy to show that the resultant deposits are composed of partially oxidized Au, corresponding to a Au-Se compound regardless the deposit morphology. To obtain a detailed characterization of the HNPs with different morphologies and to gain mechanistic insights into the deposition process, (cryogenic) high-resolution transmission electron microscopy, mass spectrometry, cyclic voltammetry, and computational simulations have been performed. Our results emphasize that the knowledge of the surface chemistry of the seed particles as well as a defined picture of the metal precursors is necessary to understand heterodeposition processes. © 2016 American Chemical Society.

  • Size-Controlled Synthesis of Sub-10-nanometer Citrate-Stabilized Gold Nanoparticles and Related Optical Properties.

    Piella J., Bastús N.G., Puntes V. Chemistry of Materials; 28 (4): 1066 - 1075. 2016. 10.1021/acs.chemmater.5b04406. IF: 9.407

    Highly monodisperse, biocompatible and functionalizable sub-10-nm citrate-stabilized gold nanoparticles (Au NPs) have been synthesized following a kinetically controlled seeded-growth strategy. The use of traces of tannic acid together with an excess of sodium citrate during nucleation is fundamental in the formation of a high number (7 × 1013 NPs/mL) of small ∼3.5 nm Au seeds with a very narrow distribution. A homogeneous nanometric growth of these seeds is then achieved by adjusting the reaction parameters: pH, temperature, sodium citrate concentration and gold precursor to seed ratio. We use this method to produce Au NPs with a precise control over their sizes between 3.5 and 10 nm and a versatile surface chemistry allowing studying the size-dependent optical properties in this transition size regime lying between clusters and nanoparticles. Interestingly, an inflection point is observed for Au NPs smaller than 8 nm in which the sensitivity of the localized surface plasmon resonance (LSPR) peak position as a function of NPs size and surface modifications dramatically increase. These studies are relevant in the design of the final selectivity, activity and compatibility of Au NPs, especially in those (bio)applications where size is a critical parameter (e.g., biodistribution, multiplex labeling, and protein interaction). © 2016 American Chemical Society.

  • Tuning the Plasmonic Response up: Hollow Cuboid Metal Nanostructures

    Genç A., Patarroyo J., Sancho-Parramon J., Arenal R., Duchamp M., Gonzalez E.E., Henrard L., Bastús N.G., Dunin-Borkowski R.E., Puntes V.F., Arbiol J. ACS Photonics; 3 (5): 770 - 779. 2016. 10.1021/acsphotonics.5b00667. IF: 5.404

    We report the fine-tuning of the localized surface plasmon resonances (LSPRs) from ultraviolet to near-infrared by nanoengineering the metal nanoparticle morphologies from solid Ag nanocubes to hollow AuAg nanoboxes and AuAg nanoframes. Spatially resolved mapping of plasmon resonances by electron energy loss spectroscopy (EELS) revealed a homogeneous distribution of highly intense plasmon resonances around the hollow nanostructures and the interaction, that is, hybridization, of inner and outer plasmon fields for the nanoframe. Experimental findings are accurately correlated with the boundary element method (BEM) simulations demonstrating that the homogeneous distribution of the plasmon resonances is the key factor for their improved plasmonic properties. As a proof of concept for these enhanced plasmonic properties, we show the effective label free sensing of bovine serum albumin (BSA) of single-walled AuAg nanoboxes in comparison with solid Au nanoparticles, demonstrating their excellent performance for future biomedical applications. © 2016 American Chemical Society.


  • Enhanced reactivity of high-index surface platinum hollow nanocrystals

    González E., Merkoçi F., Arenal R., Arbiol J., Esteve J., Bastús N.G., Puntes V. Journal of Materials Chemistry A; 4 (1): 200 - 208. 2015. 10.1039/c5ta07504a. IF: 7.443

    The precise morphological control of the surface of inorganic nanocrystals (NCs) is critical for the understanding of the unique properties of the materials at the nanoscale and useful in a wide range of applications, such as catalysis, where the development of highly active and low-cost materials represents a landmark for the development of industrial technologies. Here we show how combining solid state chemistry and colloidal synthesis allows us to prepare exotic materials, in particular, PtAg@Pt single-crystal hollow NCs with high-index planes synthesized at room temperature by controlled corrosion of silver templates, which minimize Pt consumption and maximize surface reactivity. © The Royal Society of Chemistry 2016.

  • Exploring new synthetic strategies for the production of advanced complex inorganic nanocrystals

    Bastús N.G., Gonzalez E., Esteve J., Piella J., Patarroyo J., Merkoçi F., Puntes V. Zeitschrift fur Physikalische Chemie; 229 (1-2): 65 - 83. 2015. 10.1515/zpch-2014-0611. IF: 1.356

    The design of new protocols for the colloidal synthesis of complex nanocrystals (NCs) with advanced functionalities, comprising both hybrid and hollow structures, and the study of their fundamental properties is of paramount importance for the development of a new generation of nanostructured materials. The possibility of tailoring the dimensional regime of NCs, along with its composition and structure, represents a landmark achievement in the control of their unique physico-chemical properties. These properties, alongside with the ability to cheaply produce high quality NCs in fairly large amounts by wet-chemistry techniques, leads to their potential applicability from materials science to nanomedicine. Within this context, this review is focused on describing a successful framework for designing synthetic strategies for the production of advanced complex NCs, integrating the development of new synthetic methods with its structural characterization, monitoring of their properties, and study of its reactivity. As a result, it is expected to provide new routes to produce robust and easy-to-process NCs in a wide range of sizes, shapes and configurations that can be explored to achieve the combination of all degrees of control, aiming to produce a complete and diverse library of material combinations that will expand its applicability in a wide diversity of fields. © 2014 Walter de Gruyter Berlin/Boston.

  • SERS efficiencies of micrometric polystyrene beads coated with gold and silver nanoparticles: The effect of nanoparticle size

    Mir-Simon B., Morla-Folch J., Gisbert-Quilis P., Pazos-Perez N., Xie H.-N., Bastús N.G., Puntes V., Alvarez-Puebla R.A., Guerrini L. Journal of Optics (United Kingdom); 17 (11, 114012) 2015. 10.1088/2040-8978/17/11/114012. IF: 2.059

    Rapid advances in nanofabrication techniques of reproducibly manufacturing plasmonic substrates with well-defined nanometric scale features and very large electromagnetic enhancements paved the way for the final translation of the analytical potential of surface-enhanced Raman scattering (SERS) to real applications. A vast number of different SERS substrates have been reported in the literature. Among others, discrete particles consisting of an inorganic micrometric or sub-micrometric core homogeneously coated with plasmonic nanoparticles stand out for their ease of fabrication, excellent SERS enhancing properties, long-term optical stability and remarkable experimental flexibility (manipulation, storage etc). In this article, we performed a systematic experimental study of the correlation between the size of quasi-spherical gold and silver nanoparticle and the final optical property of their corresponding assembles onto micrometric polystyrene (PS) beads. The size and composition of nanoparticles play a key role in tuning the SERS efficiency of the hybrid material at a given excitation wavelength. This study provides valuable information for the selection and optimization of the appropriate PS@NPs substrates for the desired applications. © 2015 IOP Publishing Ltd.


  • Distribution and potential toxicity of engineered inorganic nanoparticles and carbon nanostructures in biological systems

    Casals E.; Vazquez-Campos S.; Bastus N.G.; Puntes V. TrAC - Trends in Analytical Chemistry; 27 (8): 672 - 683. 2008. 10.1016/j.trac.2008.06.004.

  • Gold Nanoparticles and Microwave Irradiation Inhibit Beta-Amyloid Amyloidogenesis

    Araya Eyleen; Olmedo Ivonne; Bastus Neus G.; Guerrero Simon; Puntes Victor F.; Giralt Ernest; Kogan Marcelo J Nanoscale Research Letters; 3 (11): 435 - 443. 2008. 10.1007/s11671-008-9178-5.

  • Reactivity of engineered inorganic nanoparticles and carbon nanostructures in biological media

    Neus G. Bastús; Eudald Casals; Socorro Vázquez-Campos; Victor Puntes Nanotoxicology; 2 (3): 99 - 112. 2008. 10.1080/17435390802217830.