Arianna Friggeri

Recognition of steroids by self-assembled monolayers of calix[4]arene-resorcin[4]arene receptors

Surface plasmon resonance spectroscopy shows that a self-assembled monolayer of the calix[4]resorcin[4]arene-based receptor 1 binds steroids from aqueous solution. Binding studies with prednisolone-21-acetate, corticosterone-21-acetate, and cortisone-21-acetate, gave affinity constants between 2.0×105 and 3.5×105 m-1.

Surface‐Confined Metallodendrimers: Isolated Nanosize Molecules

The incorporation of dialkyl sulfide side chains in metallodendrimers is a simple method for their insertion into a monolayer of decanethiol formed by self-assembly on a gold surface. The dendrimer binds through the sulfide group to a defect in the monolayer on the gold surface (see picture). The surface concentration of the isolated dendrimer adsorbate can be regulated by the adsorption time (for example, 55 adsorbates on a surface of 200x200 nm(2) after 20 h).

Organogel or polymer gel; facilitated gelation of a sugar-based organic gel by the addition of a boronic acid-appended polymer

The combination of boronic acid-appended poly(L-lysine) 1 and sugar-based gelator 2 yields a novel organo-polymer gel, consisting of vesicles held together by polymer molecules.

Self-Assembled Monolayers on Gold for the Fabrication of Radioactive Stents

An innovative and easily applicable method for the fabrication of radioactive stents, to be used for the treatment of restenosis, is presented. By incorporating the b-emitting radioisotopes 186Re, 188Re, 90Y, or 32P into sulfur-containing adsorbates, it becomes possible to cover a gold surface with a radioactive self-assembled monolayer (SAM). Two methods have been investigated. In the first, SAMs consisting of potentially radioactive rhenium-, yttrium-, and phosphorus-containing adsorbates have been assembled on 2D gold substrates, after which they have been studied by wettability measurements, electrochemistry, and X-ray photoelectron spectroscopy (XPS). The stability of these SAMs under simulated physiological conditions (phosphate buffered saline, PBS solution) for periods up to two months has been demonstrated. Alternatively, potentially radioactive monolayers have been prepared by exposure of SAMs of mono-, bi-, and tridentate ligands to a solution containing a radiometal (rhenium) in order to bind the metal to the monolayer. The polydentate ligands exhibit excellent binding capacity, leading to SAMs containing over 10±10 mol/cm2 of the radiometal, which is more than sufficient to make this system viable for the delivery of therapeutical dosages of radiation.

Trägerfixierte Metallodendrimere: isolierte Moleküle im Nanomaßstab

Die Einfuhrung von Dialkylsulfidseitenketten in Metallodendrimere ist eine einfache Strategie fur deren Einbau in eine Decanthiolmonoschicht, die zuvor durch Selbstorganisation auf einer Goldoberflache gebildet wurde. Uber den Sulfidanker kann das Dendrimer in Defektstellen der Monoschicht an das Goldsubstrat binden (siehe Bild). Die Oberflachenkonzentration der isolierten Dendrimeradsorbate kann uber die Adsorptionszeit gesteuert werden (z.B. 55 Adsorbate auf einer Flache von 200×200 nm2 nach 20 h.

More than just a catalyst: a novel role for benzylamine in the sol-gel transcription or organogels

Gelator-catalyst interactions allow the transcription of the organogel structure of methyl-4,6-O-(p-nitrobenzylidene)-alpha-D-glucopyranoside (1) into its silica analogue, even in the absence of positive charges or H-bonding sites on the gelator molecule which, until now, were considered indispensable.

Self-Assembled Monolayers with Chemical Functions

Synthetic receptor molecules that can selectively bind guests can store chemical information. The trasduction of this information into electronic or optical signals gives rise to a sensor device. The integration of calix[4]arene-based receptors into polysiloxane membranes of field effect transistors provides stable chemical systems that can transduce the complexation of ionic species into electronic signals. Similarly, crown-ether, calixarene, resorcinarene, and cyclodextrin receptor molecules have been incorporated into selfassembled monolayers (SAMs) on gold and glass, for the detection of metal ions, small organic molecules, and steroids. Electrochemical impedence spectroscopy, surface plasmon resonance spectroscopy, and atomic force microscopy are some of the techniques that were used for the transduction of the host — guest interactions into measurable signals.

Self-Assembled Monolayers on Gold for the Detection of Molecular Interactions Via Surface Plasmon Resonance

Self-assembled monolayers, of receptor adsorbates, on gold have been used to detect the presence of small aromatic compounds, in water. Surface Plasmon Resonance (SPR) was used to monitor the in situhost-guest interaction processes occuring at the monolayer-water interface.