Design of maleimide-functionalised electrodes for covalent attachment of proteins through free surface cysteine groups.

Mixed two-component monolayers on glassy carbon are prepared by electrochemical oxidation of N-(2-aminoethyl)acetamide and mono-N-Boc-hexamethylenediamine in mixed solution. Subsequent N-deprotection, amide coupling and solid-phase synthetic steps lead to electrode-surface functionalisation with maleimide, with controlled partial coverage of this cysteine-binding group at appropriate dilution for covalent immobilisation of a model redox-active protein, cytochrome c, with high coverage (≈7.5 pmol cm(-2) ).