1,721,209 research outputs found
Micelles as containers for self-assembled nanodevices
No full textMicelles of nanometric dimensions are used to self-assemble two or more lipophilic molecular components. The combination of their functions produces new functions, such as fluorescent sensing of cations and pH window
Electrochemical assemblig/disasembling of helicates displaying hysteresis: storing informations in solution.
No full textDouble Helicates of Cu(I) and monomeric species of Cu(II) can be obtained using the same ligands under the same conditions. This give bistable systems whose interconversion presents hysteresis and may be used to store informations in solutio
Molecular machinery working with transition metal ions.
No full textIn this plenary lecture - given on the assignement of the "Medaglia Nasini" prize - a review of the author's research is presented, in the ion translocation and controlled molecular rearrangements are
Gold nanostars for superficial diseases: A promising tool for localized hyperthermia?
No full textA review about the use of the photothermal effect exerted by gold nanostars in superficial deseases therapie
Controlled uptake-release of the citrate anion in a system capable of pH driven triple Cu2+ translocation
No full textTriple cation translocation is controlled by pH in a tripodal ligand. The movement of the cations induces the uptake/release of a citrate anion from the multicomponent recepto
Residual and exploitable fluorescence in micellar self-assembled ON-OFF sensors for copper(II).
No full textset of new ligands, L2H(2)-L5H(2), containing the 1,4,8,11-tetraaza-5,7-dione framework has been prepared, The ligands feature lipophilic substituents either on the carbon atom in the 6 position or on the amino groups, or on both. The solution behaviour of the ligands when included in TritonX-100 micelles has been investigated by means of potentiometric titrations and protonation and complexation constants for the Cu2+ cation have been determined in micellar medium. Micellar assemblies containing the ligands and pyrene have been prepared, and coupled pH-metric and fluorimetric titrations allowed the determination of the response of the systems as ON-OFF fluorescent sensors for Cu2+. A correlation between the effective lipophilicity of the ligand and the residual fluorescence (i.e. the fluorescence of the OFF state) was observed, and with the more lipophilic ligand, L3H(2), we obtained a residual fluorescence as low as 8%, with a significant improvement with respect to other published systems. On the other hand, introduction of functionalities on the amino groups of 1,4,8,11-tetraaza-5,7-dione brings the drawback of a small but significant decrease of the exploitable fluorescence, i.e. the fluorescence of the system in the absence of added Cu2+, at the pH value suitable for full metal complexatio
Three component systems for conventional and window-shaped response pH indicators,
No full textThree-component systems made of a tetradentate bis-amino bis-quinoline ligand, a transition metal cation (Ni2+ or Cu2+) and a fluorescent indicator (Coumarin 343) have been studied in a water-dioxane (1:4 v/v) mixture, through potentiometric, pH-spectrophotometric and pH-fluorimetric titrations. For the Cu2+ containing systems, an "on-off-on" variation of fluorescence intensity vs. pH has been observed, whereas in the presence of Ni2+ a simple "on-off" profile of the fluorescence intensity vs. pH was obtained. These ternary systems thus behave as window-shaped or conventional pH-indicators, depending whether Cu2+ or Ni2+ is used as the catio
Self-Assembled Monolayers of Silver Nanoparticles: From Intrinsic to Switchable Inorganic Antibacterial Surfaces
No full textThe layer-by-layer technique allows to graft molecular monolayers on bulk surfaces that, in turn, allow to graft monolayers of metal nanoparticles. This microreview focuses on the preparation of such materials featuring a monolayer of silver nanoparticles (AgNP) and their use as antimicrobial surfaces against both planktonic bacteria and biofilms. The role of Ag+ release and of direct cell/AgNP contact in the antibacterial action will be stressed as a function of the adhesive molecular layer, of the AgNP dimension and shape, of their surface density, and of the molecular overcoating. While these surfaces display an intrinsic antibacterial action, a further evolution will also be reviewed, in which additional photothermal antibacterial action can be switched on demand, using near-IR radiation and non-spherical AgNP or a combination of AgNP with non-spherical AuNP. The intrinsic and switchable photothermal action of these surfaces will be unraveled, and their synergistic effect stresse
Methods for glass surface coating with functional Self Assembled Monolayers
No full textA modified approach is presented to efficiently coat flat galss surfaces with function molecules. An optical method to check the efficiency of the coating is also presente
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