NiII1,4,8,11-tetraazacyclotetradecane electrocatalytic films prepared on top of surface anchored PAMAM dendrimer layers. A new type of electrocatalytic material for the electrochemical oxidation of methanol.
Gold electrodes, previously prepared with surface anchored PAMAM dendrimers, were further modified with a Ni-containing tetraazamacrocycle resulting in a novel electrocatalytic material which proved to be particularly efficient for the electrochemical oxidation of methanol in basic aqueous medium.
Molecular and biomolecular optoelectronics
Abstract Reversible electronic transduction of photonic processes occurring on electrodes is the conceptual method to develop molecular and biomolecular optoelectronic systems. Cyclic photochemical activation of molecular or biomolecular monolayer redox-functions provides a general methodology for the amperometric transduction of photonic information that is recorded by the chemical assembly. Alternatively, photoisomerizable monolayers associated with electrodes act as "command interfaces" for controlling the interfacial electron transfer between molecular redox-species or redox-proteins. The systems use a photonic input for the generation of an electronic output and act as information processing assemblies. Programmed arrays of photosensitizer/electron acceptor cross-linked Au-nanoparticle arrays are assembled on indium tin oxide (ITO) for photoelectrochemical applications.
Chemical, biological, and immunological characterization of mono- and diiodothyrotropin releasing factor.
Abstract Iodination of thyrotropin releasing factor (TRF) with chloramine-T and NaI at pH 7.5 produces both mono- and diiodo-TRF as well as unreacted TRF and I − . The four compounds can be separated by ion-exchange chromatography on SP-Sephadex C-25, using a stepwise gradient of 0.01 m MH 4 OAc at pH 3.5, 5.2 and 7.2. The monoiodo-TRF was characterized by nuclear magnetic resonance, mass spectra, and elemental analysis as [Im-5-iodo-His 2 ]-TRF while the diiodo-TRF was similarly characterized as [Im-2,5-diiodo-His 2 ]-TRF. Both iodination products showed no thyrotropin releasing activity at doses up to 1 μg in the in vivo mouse bioassay. The specific binding of mono- and diiodo-TRF was measured against three different TRF antisera. In the absence of TRF, antisera A and C bound more diiodo-TRF than monoiodo-TRF while antiserum B seemed to bind both tracers equally. In all cases steeper curves were produced when diiodo-TRF was displaced by synthetic TRF.