Spectroscopical characterization of melanins is a prior requirement for the efficient tailoring of their radical scavenging, ultraviolet–visible radiation absorption, metal chelation, and natural pigment properties. Electron paramagnetic resonance (EPR), exploiting the common persistent paramagnetism of melanins, represents the elective standard for the structural and dynamical characterization of their constituting radical species. Although melanins are mainly investigated using X-band (9.5 GHz) continuous wave (CW)-EPR, an integration with the application of Q-band (34 GHz) in CW and pulse EPR for the discrimination of melanin pigments of different compositions is presented here. The longitudinal relaxation times measured highlight faster relaxation rates for cysteinyldopa melanin, compared to those of the most common dopa melanin pigment, suggesting pulse EPR spin–lattice relaxation time measurements as a complementary tool for characterization of pigments of interest for biomimetic materials engineering.

AL KHATIB, M., Costa, J., Baratto, M.C., Basosi, R., Pogni, R. (2020). Paramagnetism and relaxation dynamics in melanin biomaterials. JOURNAL OF PHYSICAL CHEMISTRY. B, CONDENSED MATTER, MATERIALS, SURFACES, INTERFACES & BIOPHYSICAL, 124(11), 2110-2115 [10.1021/acs.jpcb.9b11785].

Paramagnetism and relaxation dynamics in melanin biomaterials

Maher Al Khatib;Jessica Costa;Maria Camilla Baratto;Riccardo Basosi;Rebecca Pogni
2020-01-01

Abstract

Spectroscopical characterization of melanins is a prior requirement for the efficient tailoring of their radical scavenging, ultraviolet–visible radiation absorption, metal chelation, and natural pigment properties. Electron paramagnetic resonance (EPR), exploiting the common persistent paramagnetism of melanins, represents the elective standard for the structural and dynamical characterization of their constituting radical species. Although melanins are mainly investigated using X-band (9.5 GHz) continuous wave (CW)-EPR, an integration with the application of Q-band (34 GHz) in CW and pulse EPR for the discrimination of melanin pigments of different compositions is presented here. The longitudinal relaxation times measured highlight faster relaxation rates for cysteinyldopa melanin, compared to those of the most common dopa melanin pigment, suggesting pulse EPR spin–lattice relaxation time measurements as a complementary tool for characterization of pigments of interest for biomimetic materials engineering.
2020
AL KHATIB, M., Costa, J., Baratto, M.C., Basosi, R., Pogni, R. (2020). Paramagnetism and relaxation dynamics in melanin biomaterials. JOURNAL OF PHYSICAL CHEMISTRY. B, CONDENSED MATTER, MATERIALS, SURFACES, INTERFACES & BIOPHYSICAL, 124(11), 2110-2115 [10.1021/acs.jpcb.9b11785].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11365/1106447