RESUMEN
Small, spherical silver nanoclusters were synthesised on the surface of paper as a model cellulosic fibre substrate by a standard chemical reduction method. The concentration of the silver nanoclusters on the substrate surface is roughly proportional to the initial silver salt concentration. However, there is a noticeable degree of nanocluster aggregation to larger agglomerates. The addition of small amounts of α-cellulose, carboxymethyl cellulose or aminocellulose during the synthesis of the silver/cellulose nanocomposites suppresses this aggregation and significantly increases the concentration of the silver nanoclusters on the surface of the fibres of cellulose. These small, surface-stabilised silver nanoclusters, with the desired size and morphology, deposited from aqueous solutions on the surface of cellulosic cotton fibres, show enhanced antibacterial activity against MRSA compared to that of the corresponding silver/cotton nanocomposites prepared in the absence of a cellulosic surface stabiliser.
RESUMEN
Designs for reusable microelectrodes, which are easy to assemble and so do not require special technical skills or services for their construction, are presented. Three types of microelectrodes are fabricated by lamination of metal foil, wire, and wire grids, producing microband, microdisk, and a linear array of microdisk geometries. The electrodes themselves do not need to be polished prior to their use but are observed to be slightly recessed from the surrounding insulating surface. Good agreement is observed between experimental steady-state voltammetric results in nonaqueous solutions and the relevant analytical theory for the voltammetric current.