Tracking the formation of eumelanin from L-Dopa using coupled measurements

Philip Yip; Jens U Sutter

doi:10.1088/2050-6120/aa9724

Tracking the formation of eumelanin from L-Dopa using coupled measurements

Philip Yip, Jens U Sutter

Research output: Contribution to journal › Article

3 Citations (Scopus)

13 Downloads (Pure)

Abstract

Melanin plays a crucial role as a pigment all through the animal kingdom. Being a macromolecule just on the divide between an ordered crystalline or a purely amorphous form melanin has proven a challenge to structure-function analysis. Melanin assembles from small molecules much like a jigsaw and much like in a jigsaw the fine detail quickly vanishes in the overall picture. With melanin being first and foremost a photo-active molecule we focus on spectral properties for the characterisation of its structure. We use absorption measurements to illustrate the complex nature of the formation process. To gain a better hold on the formation pathway we use coupled measurements of excitation and emission to identify 'areas of interest' in the excitation-emission matrix (EEM). We then probe one area for characteristic fluorescence lifetimes to track one melanin building block through the formation process. Comparison of the EEMs of L-Dopa derived melanin with natural Sepia melanin shows characteristic differences. We show how the presence of copper ions creates a melanin closer to its natural form.

Original language	English
Article number	027001
Number of pages	10
Journal	Methods and Applications in Fluorescence
Volume	6
DOIs	https://doi.org/10.1088/2050-6120/aa9724
Publication status	Published - 25 Jan 2018

Fingerprint

dopa

Melanin

melanin

Melanins

Levodopa

Molecules

eumelanin

pigments

Macromolecules

macromolecules

Pigments

excitation

animals

Copper

molecules

Animals

Fluorescence

Ions

Crystalline materials

copper

Keywords

eumelanin
fluorescence lifetime
5,6-dihydroxyindole (DHI)
excitation-emission-matrix (EEM)
time-correlated-single-photon-counting (TCSPC)

Cite this

Yip, P., & Sutter, J. U. (2018). Tracking the formation of eumelanin from L-Dopa using coupled measurements. Methods and Applications in Fluorescence , 6, [027001]. https://doi.org/10.1088/2050-6120/aa9724

Yip, Philip ; Sutter, Jens U. / Tracking the formation of eumelanin from L-Dopa using coupled measurements. In: Methods and Applications in Fluorescence . 2018 ; Vol. 6.

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Yip, P & Sutter, JU 2018, 'Tracking the formation of eumelanin from L-Dopa using coupled measurements', Methods and Applications in Fluorescence , vol. 6, 027001. https://doi.org/10.1088/2050-6120/aa9724

Tracking the formation of eumelanin from L-Dopa using coupled measurements. / Yip, Philip; Sutter, Jens U.

In: Methods and Applications in Fluorescence , Vol. 6, 027001, 25.01.2018.

Research output: Contribution to journal › Article

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AU - Sutter, Jens U

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N2 - Melanin plays a crucial role as a pigment all through the animal kingdom. Being a macromolecule just on the divide between an ordered crystalline or a purely amorphous form melanin has proven a challenge to structure-function analysis. Melanin assembles from small molecules much like a jigsaw and much like in a jigsaw the fine detail quickly vanishes in the overall picture. With melanin being first and foremost a photo-active molecule we focus on spectral properties for the characterisation of its structure. We use absorption measurements to illustrate the complex nature of the formation process. To gain a better hold on the formation pathway we use coupled measurements of excitation and emission to identify 'areas of interest' in the excitation-emission matrix (EEM). We then probe one area for characteristic fluorescence lifetimes to track one melanin building block through the formation process. Comparison of the EEMs of L-Dopa derived melanin with natural Sepia melanin shows characteristic differences. We show how the presence of copper ions creates a melanin closer to its natural form.

AB - Melanin plays a crucial role as a pigment all through the animal kingdom. Being a macromolecule just on the divide between an ordered crystalline or a purely amorphous form melanin has proven a challenge to structure-function analysis. Melanin assembles from small molecules much like a jigsaw and much like in a jigsaw the fine detail quickly vanishes in the overall picture. With melanin being first and foremost a photo-active molecule we focus on spectral properties for the characterisation of its structure. We use absorption measurements to illustrate the complex nature of the formation process. To gain a better hold on the formation pathway we use coupled measurements of excitation and emission to identify 'areas of interest' in the excitation-emission matrix (EEM). We then probe one area for characteristic fluorescence lifetimes to track one melanin building block through the formation process. Comparison of the EEMs of L-Dopa derived melanin with natural Sepia melanin shows characteristic differences. We show how the presence of copper ions creates a melanin closer to its natural form.

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KW - time-correlated-single-photon-counting (TCSPC)

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