Electro-deposition of thin cellulose films at boron-doped diamond substrates

Cellulose films of variable thickness are electro-deposited from aqueous alkaline thiourea solution onto polished boron-doped diamond substrates in an anodic process. Films with "net-like" topography are formed and shown to consist of both cellulose-I and cellulose-II components. Properties of these films are investigated. When immersed in aqueous electrolyte solution, ion partitioning into the electro-deposited cellulose films occurs. The accumulation and release of two aqueous redox systems, Ru(NH3)(6)(3+/2+) and methylviologen(2+/+), is reported. Relatively slow diffusion of these cations is observed within cellulose (approximately 5 orders of magnitude slower when compared to diffusion in aqueous media). For the methylviologen(2+/+) redox system partitioning leads to irreversibility in the voltammetric response and to the preferred formation of aggregates immobilized within the cellulose film. (c) 2006 Elsevier B.V. All rights reserved.