Micaela Matta: Structure-properties of eumelanin, a mixed conducting material for next-generation organic (bio-) electronics

Organic electrochemical transistors (OECTs) have rapidly surged as amplifying transducers for biosensing or diagnostic devices and for cells/nerves stimulation [1]. These bioelectronic devices use novel water-compatible conducting polymers able to transport both ionic and electronic current [2], mimicking the fundamental signal transduction mechanisms in our cells and neurons.

A different path towards new bioelectronic materials is to instead use natural mixed conducting polymers that are intrinsically biocompatible. Synthetic polymers deriving from eumelanin (the black pigment in our skin, hair and brain) are promising biocompatible, non-cytotoxic components in OECTs [3-5] as they feature both electronic and protonic charge carriers.

I am currently studying the structure, self-assembly and electronic properties of eumelanin- derived materials using electronic structure calculations and molecular dynamics simulations. My model integrates computational and experimental information to describe the chemical disorder of eumelanin arising from its chirality, tautomerisation, oxidation and proton exchange sites to understand how eumelanin’s chemical features affect its electronic structure and charge transport characteristics.

1. Rivnay, J.; Inal, S.; Salleo, A.; Owens, R. M.; et al. Nat. Rev. Mater. 2018, 3 (2), 17086.

2. Paulsen, B. D.; Tybrandt, K.; Stavrinidou, E.; Rivnay, J. Nat. Mater. 2020, 19 (1), 13–26.

3. d’Ischia, M.; Napolitano, A.; Pezzella, A.; et al. Angew. Chemie Int. Ed. 2020, 59 (28), 11196–11205.

4. Migliaccio, L.; Manini, P.; Altamura, D.; Giannini, C.; et al. Front. Chem. 2019, 7, 162.

5. Sheliakina, M.; Mostert, A. B.; Meredith, P. Mater. Horizons 2018, 5 (2), 256–263.

6. Matta, M.; Pezzella, A.; Troisi, A. J. Phys. Chem. Lett. 2020, 11 (3), 1045–1051.