Linked Life Data

15493944

Source:http://linkedlifedata.com/resource/pubmed/id/15493944

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
42
pubmed:dateCreated
2004-10-20
pubmed:abstractText
Single-molecule (SM) spectroscopic methods were employed to study single site variations in the acidity properties of sol-gel-derived silicate films. The pH-sensitive dye Carboxy SNARF-1 (C.SNARF-1) was used to sense film acidity. Its concentration in the films was maintained at nanomolar levels to allow for SMs to be spectroscopically interrogated. The ratio of C.SNARF-1 fluorescence at 580 nm (protonated form) and 640 nm (deprotonated form) was used to characterize local film pH. SM data were acquired both for "untreated" films and for those treated by immersion for either 1 or 8 h in phosphate solutions of different pH. The SM results prove that the spectral variability observed is dominated by static variations in the local matrix acidity. Shorter immersion times lead to relatively broad histograms and broad "titration" curves, providing clear evidence for kinetic limitations to access of certain film environments by the immersion solutions. Films subjected to longer immersion times generally exhibit narrower histograms. Particularly narrow distributions were obtained for films treated near pH 8-9, while much broader histograms were produced near pH 7. These results are attributed to the buffering effects of surface silanols near pH 9 and enhanced pH sensitivity of the dye near pH 7.
pubmed:language
eng
pubmed:journal
pubmed:status
PubMed-not-MEDLINE
pubmed:month
Oct
pubmed:issn
0002-7863
pubmed:author
pubmed:copyrightInfo
Copyright 2004 American Chemical Society
pubmed:issnType
Print
pubmed:day
27
pubmed:volume
126
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
13838-44
pubmed:year
2004
pubmed:articleTitle
Single-molecule spectroscopy studies of microenvironmental acidity in silicate thin films.
pubmed:affiliation
Department of Chemistry, Kansas State University, Manhattan, Kansas 66506, USA.
pubmed:publicationType
Journal Article