Enhanced chiroptical properties of a hybrid material consisting of J-aggregates and silver nanoparticles

Trabajo presentado a la 16th International Conference on Transparent Optical Networks (ICTON), celebrada en Grazer Messe (Austria) del 6 al 10 de julio de 2014.In this paper, we report on the optical activity (circular dichroism) properties of hybrid organic/inorganic structures consisting of dye molecules in J-aggregate states and silver nanoparticles. The most striking results of this study are formation of microspherical micelles in a system of interacting J-aggregates and silver nanoparticles and strong (up to 8 times) enhancement in the optical activity of complexes of J-aggregates and silver nanoparticles as compared to the CD signal from the original J-aggregates. These experimental results might have potential applications in chiral species sensing and can provide some insights on mechanisms of self-assembly of supermolecular structures and the induction of their optical activity.Peer Reviewe

Strong enhancement of circular dichroism in a hybrid material consisting of J-aggregates and silver nanoparticles

We report on the chiroptical (circular dichroism) properties of hybrid organic/inorganic nano-and microstructures consisting of dye molecules in J-aggregate states (arranged in direct and reverse micelles) and silver nanoparticles. The main results are formation of micelles in a system of interacting J-aggregates and silver nanoparticles and strong (up to 8 times) enhancement in the optical activity of complexes of J-aggregates and silver nanoparticles as compared to the CD signal from the original J-aggregates. These experimental results might have potential applications in chiral species sensing and can provide some insights on mechanisms of self-assembly of supermolecular structures and the induction of their optical activity. © 2013 American Chemical Society.This work was in part financially supported by the ETORTEK 2011−2013 project “nanoIKER” from the Department of Industry of the Basque Government; D.S., Y.G., and Y.R. acknowledge the support received from the European Science Foundation (activity PLASMON-BIONANOSENSE) and Science Foundation Ireland (grant SFI 07/IN.1/I1862).Peer Reviewe

Intermatrix Synthesis and Characterization of Polymer-Stabilized Functional Metal and Metal Oxide Nanoparticles

Metal oxide nanoparticles (MONPs) are excellent candidates for understanding and controlling the magnetic properties of NPs through the variation of chemistry at the atomic level. In this chapter the authors describe the preparation of Fe3O4 NPs and coat them with silver within various porous polymer matrices, of both anionic and cationic functionality. One of the synthetic advantages of the intermatrix synthesis (IMS) method allows the preparation of various NP architectures. The chapter discusses the synthesis of superparamagnetic core NPs, which are represented by iron oxide NPs. When preparing core-shell NPs, it is important to know the nature of the oxidative states of the metals containing polymer-metal nanocomposites (NCs) in order to determine whether the desired composite has been synthesized. Scanning electron microscopy coupled with an energy-dispersive spectrometer (EDS), is used to characterize the polymer-NP NC material.</p

Preparation and investigation of quantum-dot-loaded hollow polymer microspheres

In this work, hollow poly(methyl methacrylate) (PMMA) microspheres loaded with CdSe/CdS core-shell quantum dots (QDs) were fabricated onto hydrophilic glass substrates using a spray-drying method. The PMMA microspheres were investigated using scanning electron microscopy, confocal microscopy, and fluorescent lifetime imaging microscopy (FLIM) to investigate the morphology of the spheres and confirm their hollow structure. The QDs were used as fluorophores in confocal microscopy to observe the central cavity of the microspheres and in solid-state photoluminescence spectroscopy to observe whispering gallery modes (WGMs), demonstrating the high optical quality of the hollow microspheres and their potential application as optical microresonators. © 2013 American Chemical Society.We thank Science Foundation Ireland (Grant SFI 07/IN.1/I1862), Trinity College Dublin, Higher Education Authority, and Ministry of Education and Science of the Russian Federation (Grant 14.B25.31.0002) for financial support.Peer Reviewe

Optical properties of hollow polymer microspheres loaded with semiconductor quantum dots

Trabajo presentado a la 16th International Conference on Transparent Optical Networks (ICTON), celebrada en Grazer Messe (Austria) del 6 al 10 de julio de 2014.In this paper, we report on fabrication and optical properties of hollow poly(methyl methacrylate) (PMMA) microspheres loaded with CdSe/CdS core-shell quantum dots. The PMMA microspheres were fabricated using a spray-drying method and investigated using scanning electron microscopy, confocal microscopy, and fluorescent lifetime imaging microscopy. Micro-photoluminescence studies of individual microspheres were also performed revealing pronounced whispering gallery modes. This result demonstrates the high optical quality of the hollow microspheres and their potential application as optical microresonatorsPeer Reviewe