Characterization of hemicyanine Langmuir-Blodgett films by picosecond time-resolved fluorescence

Hemicyanine Langmuir–Blodgett films have been elaborated and characterized using stationary and time-resolved spectroscopic techniques. Depending on the experimental conditions, especially the pH of the water subphase, the absorption spectra of the films indicate the presence of non-fluorescent Haggregates in the monolayer. Time-resolved fluorescence measurements revealed three mono-exponential decay times: a very short one (20–23 ps) attributed to an excited intramolecular charge transfer state and two longer ones (100–120 ps and 400–590 ps) attributed to thephotoisomerization of the chromophores

Two-dimensional Arrays of Amphiphilic Zn2+ -cyclens for Guided Molecular Recognition at Interfaces

The sterically guided molecular recognition of nucleobases, phosphates, adenosine, and uridine nucleotides on Langmuir monolayers and Langmuir-Blodgett monolayers of amphiphilic mono- or bis(Zn2+-cyclen)s assembled on thiolated surfaces was investigated. The stepwise selective binding of metal ions, uracil, or phosphate by dicetyl cyclen monolayers with variously tuned structures at the air/water interface was corroborated by the measurements of the corresponding LB films deposited onto quartz crystals. Two types of recognition surfaces were fabricated from Zn2+-dicetyl cyclen. The surface covered with a complex preformed in the Langmuir monolayer was capable both of imide and of phosphate binding. The similar complex formed directly in an LB film on thiolated gold was inactive with respect to imide. The surface plasmon resonance measurements evidenced the stepwise assembly of complementary nucleotides on SAM/LB templates through consecutive phosphate-Zn2+-cyclen coordination. Base pairing between nucleotides resulted in a formation of A-U bilayers comprising two complementary monolayers. Finally, we report on SAM/LB patterns designed for divalent molecular recognition of uridine phosphate by amphiphilic bis(Zn2+-cyclen)

Hugh Tracey memorial service

Reading of poems from Mrs Shaw entitled 'Work without hope' by Samuel Taylor Carridge and 'Not to sleep' by Dante Gabriel Rezete Mrs Stewart reading lines taken from Cecil Roberts' autobiography 'Some China shadow' published by Hudson StutonReading from Mrs Stewart lines taken from Cecil Roberts' autobiography 'Some China shadow' published by Hudson StutonReading of poem from Miss June Ridgeway entitled 'Forget not yet'Reading of poem from Mrs Bush entitled 'High hills' by George Winter Pro Youn

A metal-responsive interdigitated bilayer for selective quantification of mercury( ii ) traces by surface plasmon resonance

International audienceReusable surface plasmon resonance chips allowing the quantitative and selective detection of mercury(II) ions in water at the 0.01 nM level are reported. The surface-modified gold sensor consists of a rarefied self-assembled monolayer of octanethiol topped with a Langmuir–Blodgett monolayer of an amphiphilic and highly-specific chelator. The interdigitated architecture confers to the bilayer a high packing density, surface coverage, and binding-group accessibility