Effect of Poly(amine)s on the Redox Properties of Carboxymethylcellulose and Ferrocene-modified Poly(amine) Layer-by-Layer Films

Multilayer films consisting of carboxymethylcellulose (CMC) and ferrocene-modified poly(ethyleneimine) (Fc-PEI) or poly(allylamine hydrochloride) (Fc-PAH) were successfully prepared on a gold electrode to examine their redox properties. The redox current of (Fc-PEI/CMC)_n film-coated electrodes increased with the number of layers, while the (Fc-PAH/CMC)_n film-coated electrodes exhibited increased response only for the first eight bilayers. The (Fc-PEI/CMC)_n and (Fc-PAH/CMC)_n films deposited on the surface of Fc-free multilayer film-coated electrodes also showed a redox response. The (PEI/CMC)₅ film-coated electrode showed redox responses in Fc-PEI and Fc-PAH solutions, confirming the uptake of the Fc-polymers in the inner film. In contrast, the uptake of the Fc-polymers in the (PAH/CMC)₅ film was severely suppressed, suggesting that different permeability of (PEI/CMC)₅ and (PAH/CMC)₅ films.