Preparation of multilayer films containing a crown heteropolyanion and an osmium functionalised pyrrole monomer

A layer-by-layer (LBL) deposition technique based on the electrostatic attraction of oppositely charged species has been employed to fabricate multilayer films consisting of the crown heteropolyanion, K28Li5H7P8W48O184 · 92H2O ([P8W48]40−), and the Os2+ functionalised pyrrole monomer, osmium-bis-N,N′-(2,2′-bipyridyl)-N-(pyridine-4-yl-methyl-(8-pyrrole-1-yl-octyl)-amine)chloride (BPPA–Os) on a glassy carbon electrode (GCE) initially modified with a monolayer of 4-aminobenzoic acid. The multilayer films were then characterized by cyclic voltammetry (CV). The films were found to be both uniform and stable, whilst exhibiting good electrocatalytic activity towards both nitrite and hydrogen peroxide.