Adrián Fernández-Lodeiro

Polyamine Ligand-Mediated Self-Assembly of Gold and Silver Nanoparticles into Chainlike Structures in Aqueous Solution: Towards New Nanostructured Chemosensors

Polyamine ligands are very versatile compounds due to their water solubility and flexibility. In the present work, we have exploited the binding ability of a polyamine molecular linker (L2−) bearing different functional groups, which favors the self-assembling of silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) into 1D nanochains in aqueous solution. The chainlike assemblies of AuNPs and AgNPs were structurally stable for a long period of time, during which their characteristic optical properties remained unchanged. The mechanism of AuNPs and AgNPs chain assembly associated with the induction of electric dipole–dipole interactions arising from the partial ligand exchange of surface-adsorbed citrate ions by (L2−) was investigated. UV/Vis spectrophotometry and transmission electron microscopy (TEM) were used to determine timedependent structural changes associated with formation of the 1D nanoparticle structures. Finally, the sensing of Hg2+ in aqueous solution using AgNPs@(L)2− and AuNPs@(L)2− assemblies was also carried out in aqueous solution.

Green and Red Fluorescent Dyes for Translational Applications in Imaging and Sensing Analytes: A Dual-Color Flag

Abstract Invited for this months cover picture is the BIOSCOPE group of Professors Carlos Lodeiro and José Luis Capelo at the REQUIMTE/UCIBIO‐LAQv‐FCT University NOVA of Lisbon (Portugal), and their collaborators. The cover picture is devoted to Translational Research, and shows the Portuguese Flag represented by the interaction between cells and Janus gold/silver nanoparticles functionalized with rhodamine (red) and Fluorescein (green) dyes as tools for biomedical translational research. Read the full text of their Review at 10.1002/open.201700135.

Toxicity study of new metal nanoparticles functionalized with fluorescein derivatives as novel image systems

** and M.S. Diniz* *REQUIMTE, Departamento de Quimica, Faculdade de Ciencias e Tecnologia, Centro de Quimica Fina e Biotecnologia, Universidade Nova de Lisboa, 2829-516 Caparica. **BIOSCOPE Group, Physical-Chemistry Department, Faculty of Science, Campus Ourense, University of Vigo, 32004, Ourense, Spain. Nanoparticles in general (NPs) and/or nanomaterials offer remarkable opportunities in industrial production, daily consumables, medicine, biotechnology, electronics and numerous other important commercial and economical areas. Among all these areas, nanomedicine has opened novel treatments for problematic diseases such as viral, genetic, cancer, AIDS, etc. There is limited information available regarding translocation and distribution of NPs in the body and in the environment. Additionally, there is also need for more information on NPs toxicity. Recently has been demonstrated that physiological barriers such as pulmonary and gastro-intestinal tract are affected [1,2]. The main objective of this work is to use functionalized metal NPs, as emissive agent markers, assess their internalization in cells and evaluate toxicity to cells. Using the emissive two probes synthesized in a one-pot reaction using fluoresceine as chromophore, several gold (Au), round shape, and silver (Ag) NPs (round and triangular shapes) were functionalized in organic media and water by Brust [3] and Turkevish [4] methodology, using tetraoctylammonium bromide (TOABr) as a common stabilizer and sodium borohydride as reducing agent. All has been characterized by UV-vis and emission spectroscopy, transmission electron microscopy (TEM) (Figure 1), and Light scattering. To study the route of internalization into the cell NP-complexes were injected intraperitoneally in fish (

Synthesis and Characterization of PtTe 2 Multi-Crystallite Nanoparticles using Organotellurium Nanocomposites

Herein, we report the synthesis of new PtTe2 multi-crystallite nanoparticles (NPs) in different sizes through an annealing process using new nanostructured Pt-Te organometallic NPs as a single source precursor. This precursor was obtained in a single reaction step using Ph2Te2 and H2PtCl6 and could be successfully size controlled in the nanoscale range. The resulting organometallic composite precursor could be thermally decomposed in 1,5 pentanediol to yield the new PtTe2 multi-crystallite NPs. The final size of the multi-crystallite spheres was successfully controlled by selecting the nanoprecursor size. The sizes of the PtTe2 crystallites formed using the large spheres were estimated to be in the range of 2.5–6.5 nm. The results provide information relevant to understanding specific mechanistic aspects related to the synthesis of organometallic nanomaterials and nanocrystals based on platinum and tellurium.

Cover Picture: Polyamine Ligand-Mediated Self-Assembly of Gold and Silver Nanoparticles into Chainlike Structures in Aqueous Solution: Towards New Nanostructured Chemosensors (ChemistryOpen 5-6/2013)

Cover Picture Adrián Fernández-Lodeiro, Javier Fernández-Lodeiro, Cristina Núñez*, Rufina Bastida, José Luis Capelo, and Carlos Lodeiro* The cover picture shows the formation of one-dimensional nanochains of silver nanoparticles (AgNPs) upon addition of a polyamine molecular linker. In the present work, the binding ability of this linker was exploited, bearing different functional groups, which favors the self-assembly of silver and gold nanoparticles (AuNPs) into one-dimensional nanochains in aqueous solution. These nanochains visually resemble the artistic work of “calceteiros” (pavers) to build the “calçada Portuguesa” (Portuguese pavements) in Portugal (Photography “calçada Portuguesa”, Jose M. G. Pereira). Polyamine ligands are very versatile materials due to their water solubility and flexibility. The study of AgNPs and AuNPs in one-dimensional nanostructured formations are finally used as new sophisticated heavy metal (Hg2+) ion chemosensors. For more details, see the Full Paper by Carlos Lodeiro, Christina Núñez and co-workers, on p. 200 ff.

N1-((1H-Indazol-5-yl)methylene)-N2-(2-((2-((2-(((1H-indazol-6-yl)methylene)amino)ethyl)amino)ethyl)amino)ethyl)ethane-1,2-diamine

Abstract: One novel molecular emissive probe L has been synthesized by classical Schiff-base reaction between 1H-indazole-6-carboxaldehyde and tetraethylenepentamine. The structure of compound L was confirmed by melting point, elemental analysis, ESI-MS spectrometry and by IR and 13 C-NMR and 1 H-NMR spectroscopy. Keywords: imine compounds; amine compounds; indazol Indazole ring systems have an interesting chemistry, which has been used in biology, catalysis, and medicinal chemistry [1]. Although rare in nature [2], indazoles exhibit a variety of biological activities such as HIV protease inhibition [3–5], antiarrhythmic and analgesic activities [6], antitumor activity [7,8], and antihypertensive properties [9]. Furthermore, antimicrobial and antineoplastic activities have also been shown to be associated with certain indazole derivatives [10]. As a part of our ongoing research into the design and synthesis of novel organic molecular probes, luminescent materials and MALDI-TOF-MS matrices [11–14], here we report the synthesis and

N1-(Benzo[b]thiophen-3-ylmethylidene)-N2-(2-((2-((2-(benzo[b]thiophen-3-ylmethylidene)amino)ethyl)amino)ethyl)amino)ethyl)ethane-1,2-diamine

A novel probe L has been synthesized by classical Schiff-base reaction between 1-benzothiophene-3-carbaldehyde and tetraethylenepentamine as diamine. The structure of compound L was confirmed by melting point, elemental analysis, ESI-MS spectrometry, IR and 13C-NMR and 1H-NMR spectroscopy.