title: Morphology of synthetic DOPA-eumelanin deposited on glass and mica substrates: an atomic force microscopy investigation.
abstract: Bright field microscopy and atomic force microscopy techniques are used to investigate morphological properties of synthetic eumelanin, obtained by oxidation of L-DOPA solution, deposited on glass and mica substrates. Deposits of eumelanin are characterized by aggregates with different shape and size. On a micrometric scale, filamentous as well as granular structures are present on glass and mica substrates, with a larger density on the former than on the latter. On a nanometric scale, filamentous aggregates, several microns long and about 100 nm wide and high, and granular aggregates, ∼50 nm high and 100 nm wide, are found on both substrates, whereas point-like deposits less than 10nm high and less than 50 nm wide are found on mica substrate. Dynamic light scattering measurements and atomic force microscopy images support the evidence that eumelanin presents only nanometric point-like aggregates in aqueous solution, whereas such nanoaggregates organize themselves according to granular and filamentous structures when deposition occurs, as a consequence of interactions with the substrate surface.
authors: Dipartimento di Medicina Clinica e Sperimentale, Università degli studi di Foggia, Viale Pinto, 71122 Foggia, Italy.
authors: G
authors: G
authors: Perna
authors: Dipartimento di Medicina Clinica e Sperimentale, Università degli studi di Foggia, Viale Pinto, 71122 Foggia, Italy.
authors: M
authors: M
authors: Lasalvia
authors: Dipartimento di Medicina Clinica e Sperimentale, Università degli studi di Foggia, Viale Pinto, 71122 Foggia, Italy.
authors: P
authors: P
authors: D'Antonio
authors: CNR-IPCF, Istituto per i Processi Chimico-Fisici, UOS di Bari, 70126 Bari, Italy.
authors: A
authors: A
authors: Mallardi
authors: CSGI and Dipartimento di Chimica, Università di Bari, Via Orabona 4, 70126 Bari, Italy.
authors: G
authors: G
authors: Palazzo
authors: Dipartimento di Medicina Clinica e Sperimentale, Università degli studi di Foggia, Viale Pinto, 71122 Foggia, Italy.
authors: D
authors: D
authors: Fiocco
authors: Dipartimento di Scienze Mediche di Base, Neuroscienze ed Organi di Senso, Università degli Studi di Bari "Aldo Moro", Policlinico-Piazza Giulio Cesare, 70124 Bari, Italy.
authors: A
authors: A
authors: Gallone
authors: Dipartimento di Medicina Clinica e Sperimentale, Università degli studi di Foggia, Viale Pinto, 71122 Foggia, Italy.
authors: R
authors: R
authors: Cicero
authors: Dipartimento di Medicina Clinica e Sperimentale, Università degli studi di Foggia, Viale Pinto, 71122 Foggia, Italy. Electronic address: vito.capozzi@unifg.it.
authors: V
authors: V
authors: Capozzi
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry*; D005898:Glass / Q000737:chemistry*; D007980:Levodopa / Q000737:chemistry*; D008543:Melanins / Q000737:chemistry*; D018625:Microscopy, Atomic Force / Q000379:methods; D012996:Solutions / Q000737:chemistry
chemical_list: D000538:Aluminum Silicates; D008543:Melanins; D012996:Solutions; C041877:eumelanin; D007980:Levodopa; C011934:mica
keywords: Atomic force microscopy; Dynamic light scattering; Eumelanin; Optical microscopy