Direct observation of cations and polynucleotides explains polyion absorption to like-charged surfaces

Article Abstract:

An experimental approach is described for directly observing the condensation of polynucleotides and their electrolyte counterions at a liquid/solid interface. Observations and model demonstrates that polynucleotide absorption to a like charge surface via divalent ions in virtue of a cooperative effect does not require the bridging mechanism of the Sn(super 2+) to both the surface and the nucleotide, nor the charge inversion of the surface or of the polynucleotide.

User Contributions:

Comment about this article or add new information about this topic:

Comment:  (50-4000 characters)

Name:

E-mail:

Security Code:

Femtosecond fluorescence dynamics of porphyrin in solution and solid films: The effects of aggregation and interfacial electron transfer between porphyrin and TiO2

Article Abstract:

The exited-state relaxation dynamics of a synthetic porphyrin, ZnCAPEBPP in solution coated on a glass substrate as solid films mixed with PMMA and coated on a glass substrate as solid film and sensitized on nanocrystalline TiO2 films are investigated by using femtosecond fluorescence up-conversion spectroscopy with S2 excitation. Results have demonstrated the significance of aggregation affecting the observed relaxation dynamics in the solid phase.

User Contributions:

Comment about this article or add new information about this topic:

Comment:  (50-4000 characters)

Name:

E-mail:

Security Code:

Comparative X-ray standing wave analysis of metal-phosphate multilayer films of dodecane and porphyrin molecular square

Article Abstract:

A study demonstrates that long-period X-ray standing wave (XSW) analysis is a very useful probe of the structure of layer-by-layer assembled metal phosphonate films. The method provides a simultaneous measurement from multiple atomic distribution profiles of various shapes and sizes over length scales of 1-20 nm.

User Contributions:

Comment about this article or add new information about this topic:

Comment:  (50-4000 characters)

Name:

E-mail:

Security Code: