Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1992-12-23
pubmed:abstractText
There is widespread acceptance that singlet oxygen is a key intermediate on one of the pathways leading to the phenomenon of photodynamic action. However, the identification of this moiety within a particular biological system and the determination of a direct link between its presence and a particular photodynamic effect is a goal which photobiologists have hitherto failed to achieve. The aim of this review is to assess the problems associated with such a goal and methods whereby they might be overcome. Initially the general photochemical and environmental factors which govern the ability of a photosensitizer to promote photodynamic action via the intermediacy of singlet oxygen are introduced and the fundamental parameters defining the formation, decay and reactivity of this species summarized. The experimental requirements for relating a particular photodynamic effect to singlet oxygen intermediacy are then analysed and the intrinsic properties of singlet oxygen which will influence this goal are discussed. Having concluded that the singlet oxygen detection method of choice for this purpose is that in which the IR emission at 1269 nm of this molecule is monitored, the advantages and disadvantages of pulsed and continuous wave photoexcitation of cellular systems are analysed. It becomes evident that, no matter what the future improvements in instrumentation are likely to be, the inherent natures of singlet oxygen and the biological system lead to a kinetic situation which will preclude a successful time-resolved solution to this problem. In contrast, experimentation with continuous wave systems holds out significant hope for the future. In particular, the use of phase modulation techniques to overcome background emission problems, the enhancement of photosensitizer optical densities as a consequence of higher extinction coefficients and/or improved photosensitizer delivery systems and the use of high power lasers and/or improved light delivery systems can, at least in principle, lead to the solution of the problem addressed herein.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
1011-1344
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
14
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
159-76
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Current perspectives of singlet oxygen detection in biological environments.
pubmed:affiliation
Chemistry Department, University of Manchester, UK.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Review, Research Support, Non-U.S. Gov't