Abstract:
:Gold nanoparticles quench the fluorescence of cationic polyfluorene with Stern-Volmer constants (KSV) approaching 1011 M-1, several orders of magnitude larger than any previously reported conjugated polymer-quencher pair and 9-10 orders of magnitude larger than small molecule dye-quencher pairs. The dependence of KSV on ionic strength, charge and conjugation length of the polymer, and the dimensions (and thus optical properties) of the nanoparticles suggests that three factors account for this extraordinary efficiency: (i) amplification of the quenching via rapid internal energy or electron transfer, (ii) electrostatic interactions between the cationic polymer and anionic nanoparticles, and (iii) the ability of gold nanoparticles to quench via efficient energy transfer. As a result of this extraordinarily high KSV, quenching can be observed even at subpicomolar concentrations of nanoparticles, suggesting that the combination of conjugated polymers with these nanomaterials can potentially lead to improved sensitivity in optical biosensors.
journal_name
Proc Natl Acad Sci U S Aauthors
Fan C,Wang S,Hong JW,Bazan GC,Plaxco KW,Heeger AJdoi
10.1073/pnas.1132025100keywords:
subject
Has Abstractpub_date
2003-05-27 00:00:00pages
6297-301issue
11eissn
0027-8424issn
1091-6490pii
1132025100journal_volume
100pub_type
杂志文章abstract::Cell type in Saccharomyces yeasts is regulated by two transposable blocks of DNA, the a and alpha cassettes. There are three loci where either cassette can exist. At the HML and HMR loci the cassettes are not expressed. The cassette at the MAT locus is expressed and controls the cell type. Changes of cell type involve...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:2018-01-09 00:00:00