53 research outputs found
Organic nanofibers embedding stimuli-responsive threaded molecular components
While most of the studies on molecular machines have been performed in
solution, interfacing these supramolecular systems with solid-state
nanostructures and materials is very important in view of their utilization in
sensing components working by chemical and photonic actuation. Host polymeric
materials, and particularly polymer nanofibers, enable the manipulation of the
functional molecules constituting molecular machines, and provide a way to
induce and control the supramolecular organization. Here, we present
electrospun nanocomposites embedding a self-assembling rotaxane-type system
that is responsive to both optical (UV-visible light) and chemical (acid/base)
stimuli. The system includes a molecular axle comprised of a dibenzylammonium
recognition site and two azobenzene end groups, and a dibenzo[24]crown-8
molecular ring. The dethreading and rethreading of the molecular components in
nanofibers induced by exposure to base and acid vapors, as well as the
photoisomerization of the azobenzene end groups, occur in a similar manner to
what observed in solution. Importantly, however, the nanoscale mechanical
function following external chemical stimuli induces a measurable variation of
the macroscopic mechanical properties of nanofibers aligned in arrays, whose
Young's modulus is significantly enhanced upon dethreading of the axles from
the rings. These composite nanosystems show therefore great potential for
application in chemical sensors, photonic actuators and environmentally
responsive materials.Comment: 39 pages, 16 figure
Free Energy Barrier for Molecular Motions in Bistable [2]Rotaxane Molecular Electronic Devices
Synthesis and characterisation of fluorescently doped mesoporous nanoparticles for two-photon excitation.
International audienc
Functionalization of two-photon dye-doped mesoporous silica nanoparticles with folic acid. Cytotoxicity studies with folate receptor positive cancer cells.
International audienc
Mesoporous silica nanoparticles combining two-photon excited fluorescence and magnetic properties
A new approach to the synthesis of multifunctional nanoparticles was developed by using covalent anchoring of cyano-bridged coordination polymer Ni2+/[Fe(CN)6]3- to the surface of two-photon dyedoped mesoporous silica nanoparticles. The obtained hybrid nanoparticles were studied by infrared (IR) spectroscopy, nitrogen adsorption (BET), X-ray diffraction, transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), luminescence, and magnetic analysis. The synthesis leads to homogeneously dispersed uni-shaped nanoparticles of around 100 nm in length that are coated with cyano-bridged metallic coordination polymer nanoparticles. These
hybrid nanoparticles combine effective two-photon excited fluorescence, porosity, high transverse nuclear relaxivity values (i.e. the magnetic resonance imaging efficiency) and superparamagnetic properties
Synthesis of Copper(I) Catenanes Incorporating a Disulfide Bridge and Their Deposition on a Gold Surface
Identification of MRC2 and CD209 receptors as targets for photodynamic therapy of retinoblastoma using mesoporous silica nanoparticles
International audienc
Syntheses, crystal structures and fluorescent properties of two d 10-metal coordination polymers based on 1,5-naphthalenedisulfonic acid
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