Electrochimica Acta, Vol.43, No.23, 3489-3496, 1998
Characterisation of electrosynthetic L-dopa-melanin films by electrochemical and spectroelectrochemical techniques
Melanin was electrochemically synthesised by the oxidation of L-dopa in aqueous medium. The intermediates of the oxidation process were characterised by cyclic voltammetry and spectroelectrochemistry. The final product of melanin oxidation exhibited properties of a heterogeneous system containing a mixture of quinones and other oxidation intermediates of L-dopa. The charge transport properties of the redox polymeric compound was studied by chronocoulometric techniques using phosphate, perchlorate and sulphonate as electrolytes. The melanin electron transport coefficient ((DeCes)-C-1/2) estimated for melanin in the various electrolytes are in good agreement with what is reported for other redox polymers. UV spectroelectrochemical reactivities of the melanogenesis process was used to identify some of the intermediate products. The excellent charge transport characteristics of melanin and its redox characteristics suggest that it could be used as an efficient immobilisation matrix for biomolecules in constructing reagentless amperometric biosensors.