The effect of copper on eumelanin photophysics and morphology

Research output: Chapter in Book/Report/Conference proceedingConference contribution book

4 Citations (Scopus)

Abstract

Despite being an important pigment in skin, hair, the eye and the brain, melanin remains one of the most enigmatic of pigments. Although the main constituents of melanin are known to be dihydroxyindoles, its photophysics is complex and
its detailed structure remains unknown. In this work we have arrested prior to completion the usual synthesis of eumelanin formed via auto-oxidation of 3, 4-dihydroxy-L-phenylalanine (L-DOPA), by the addition of copper ions. Using fluorescence techniques we report how copper modifies the self assembly of eumelanin by reducing the time to the onset of aggregation at pH 10 and yet produces simplified photophysics in terms of a clearly-defined fluorescence
spectrum and a fluorescence decay that is described well by a dominant single lifetime of ~ 6ns. This behavior isconsistent with copper inducing an enhanced abundance of 5,5-dihydroxyindole-2-carboxylic acid (DHICA). Metal ion
binding to melanin is of particular importance to neurology and has potential applications in optoelectronics.
LanguageEnglish
Title of host publicationImaging, Manipulation, and Analysis of Biomolecules, Cells, and Tissues XI
EditorsDaniel L. Farkas, Dan V Nicolau, Robert C Leif
Place of PublicationSan Francisco, California
Number of pages6
Volume8587
DOIs
Publication statusPublished - 2013

Publication series

NameProgress in biomedical optics and imaging
PublisherSPIE
No.23
Volume14

Fingerprint

melanin
pigments
copper
neurology
fluorescence
phenylalanine
hair
carboxylic acids
brain
self assembly
life (durability)
oxidation
decay
synthesis
metals
ions

Keywords

  • thioflavin T
  • aggregation
  • fluorescence
  • L-DOPA
  • copper ions
  • 4-dihydroxy-L-phenylalanine

Cite this

Birch, D. J. S., & Sutter, J. (2013). The effect of copper on eumelanin photophysics and morphology. In D. L. Farkas, D. V. Nicolau, & R. C. Leif (Eds.), Imaging, Manipulation, and Analysis of Biomolecules, Cells, and Tissues XI (Vol. 8587). (Progress in biomedical optics and imaging; Vol. 14, No. 23). San Francisco, California. https://doi.org/10.1117/12.999948
Birch, David J S ; Sutter, Jens. / The effect of copper on eumelanin photophysics and morphology. Imaging, Manipulation, and Analysis of Biomolecules, Cells, and Tissues XI. editor / Daniel L. Farkas ; Dan V Nicolau ; Robert C Leif. Vol. 8587 San Francisco, California, 2013. (Progress in biomedical optics and imaging; 23).
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abstract = "Despite being an important pigment in skin, hair, the eye and the brain, melanin remains one of the most enigmatic of pigments. Although the main constituents of melanin are known to be dihydroxyindoles, its photophysics is complex andits detailed structure remains unknown. In this work we have arrested prior to completion the usual synthesis of eumelanin formed via auto-oxidation of 3, 4-dihydroxy-L-phenylalanine (L-DOPA), by the addition of copper ions. Using fluorescence techniques we report how copper modifies the self assembly of eumelanin by reducing the time to the onset of aggregation at pH 10 and yet produces simplified photophysics in terms of a clearly-defined fluorescencespectrum and a fluorescence decay that is described well by a dominant single lifetime of ~ 6ns. This behavior isconsistent with copper inducing an enhanced abundance of 5,5-dihydroxyindole-2-carboxylic acid (DHICA). Metal ionbinding to melanin is of particular importance to neurology and has potential applications in optoelectronics.",
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Birch, DJS & Sutter, J 2013, The effect of copper on eumelanin photophysics and morphology. in DL Farkas, DV Nicolau & RC Leif (eds), Imaging, Manipulation, and Analysis of Biomolecules, Cells, and Tissues XI. vol. 8587, Progress in biomedical optics and imaging, no. 23, vol. 14, San Francisco, California. https://doi.org/10.1117/12.999948

The effect of copper on eumelanin photophysics and morphology. / Birch, David J S; Sutter, Jens.

Imaging, Manipulation, and Analysis of Biomolecules, Cells, and Tissues XI. ed. / Daniel L. Farkas; Dan V Nicolau; Robert C Leif. Vol. 8587 San Francisco, California, 2013. (Progress in biomedical optics and imaging; Vol. 14, No. 23).

Research output: Chapter in Book/Report/Conference proceedingConference contribution book

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N2 - Despite being an important pigment in skin, hair, the eye and the brain, melanin remains one of the most enigmatic of pigments. Although the main constituents of melanin are known to be dihydroxyindoles, its photophysics is complex andits detailed structure remains unknown. In this work we have arrested prior to completion the usual synthesis of eumelanin formed via auto-oxidation of 3, 4-dihydroxy-L-phenylalanine (L-DOPA), by the addition of copper ions. Using fluorescence techniques we report how copper modifies the self assembly of eumelanin by reducing the time to the onset of aggregation at pH 10 and yet produces simplified photophysics in terms of a clearly-defined fluorescencespectrum and a fluorescence decay that is described well by a dominant single lifetime of ~ 6ns. This behavior isconsistent with copper inducing an enhanced abundance of 5,5-dihydroxyindole-2-carboxylic acid (DHICA). Metal ionbinding to melanin is of particular importance to neurology and has potential applications in optoelectronics.

AB - Despite being an important pigment in skin, hair, the eye and the brain, melanin remains one of the most enigmatic of pigments. Although the main constituents of melanin are known to be dihydroxyindoles, its photophysics is complex andits detailed structure remains unknown. In this work we have arrested prior to completion the usual synthesis of eumelanin formed via auto-oxidation of 3, 4-dihydroxy-L-phenylalanine (L-DOPA), by the addition of copper ions. Using fluorescence techniques we report how copper modifies the self assembly of eumelanin by reducing the time to the onset of aggregation at pH 10 and yet produces simplified photophysics in terms of a clearly-defined fluorescencespectrum and a fluorescence decay that is described well by a dominant single lifetime of ~ 6ns. This behavior isconsistent with copper inducing an enhanced abundance of 5,5-dihydroxyindole-2-carboxylic acid (DHICA). Metal ionbinding to melanin is of particular importance to neurology and has potential applications in optoelectronics.

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Birch DJS, Sutter J. The effect of copper on eumelanin photophysics and morphology. In Farkas DL, Nicolau DV, Leif RC, editors, Imaging, Manipulation, and Analysis of Biomolecules, Cells, and Tissues XI. Vol. 8587. San Francisco, California. 2013. (Progress in biomedical optics and imaging; 23). https://doi.org/10.1117/12.999948