title: Polyamine ligand-mediated self-assembly of gold and silver nanoparticles into chainlike structures in aqueous solution: towards new nanostructured chemosensors.
abstract: 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 (L (2-)) 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 (L (2-)) 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 Hg(2+) in aqueous solution using AgNPs@(L)(2-) and AuNPs@(L)(2-) assemblies was also carried out in aqueous solution.
authors.affiliation: BIOSCOPE Group, REQUIMTE-CQFB, Chemistry Department, Faculty of Science and Technology, University NOVA of Lisbon 2829-516, Monte da Caparica (Portugal) E-mail: cristina.nunez@fct.unl.ptcle@fct.unl.pt.
authors.forename: Adrián
authors.initials: A
authors.lastname: Fernández-Lodeiro
authors.affiliation: BIOSCOPE Group, REQUIMTE-CQFB, Chemistry Department, Faculty of Science and Technology, University NOVA of Lisbon 2829-516, Monte da Caparica (Portugal) E-mail: cristina.nunez@fct.unl.ptcle@fct.unl.pt.
authors.forename: Javier
authors.initials: J
authors.lastname: Fernández-Lodeiro
authors.affiliation: BIOSCOPE Group, REQUIMTE-CQFB, Chemistry Department, Faculty of Science and Technology, University NOVA of Lisbon 2829-516, Monte da Caparica (Portugal) E-mail: cristina.nunez@fct.unl.ptcle@fct.unl.pt ; Ecology Research Group, Department of Geographical and Life Sciences, Canterbury Christ Church University CT1 1QU, Canterbury (UK).
authors.forename: Cristina
authors.initials: C
authors.lastname: Núñez
authors.affiliation: Inorganic Chemistry Department, Faculty of Chemistry, University of Santiago de Compostela 15782 Santiago de Compostela (Spain).
authors.forename: Rufina
authors.initials: R
authors.lastname: Bastida
authors.affiliation: BIOSCOPE Group, REQUIMTE-CQFB, Chemistry Department, Faculty of Science and Technology, University NOVA of Lisbon 2829-516, Monte da Caparica (Portugal) E-mail: cristina.nunez@fct.unl.ptcle@fct.unl.pt.
authors.forename: José Luis
authors.initials: JL
authors.lastname: Capelo
authors.affiliation: BIOSCOPE Group, REQUIMTE-CQFB, Chemistry Department, Faculty of Science and Technology, University NOVA of Lisbon 2829-516, Monte da Caparica (Portugal) E-mail: cristina.nunez@fct.unl.ptcle@fct.unl.pt.
authors.forename: Carlos
authors.initials: C
authors.lastname: Lodeiro
keywords: 1D nanochains; gold; mercury; nanoparticles; self-assembly; silver