Immobilization of electroactive molecules in organized thin films

Redox mediators were immobilized in ordered thin films of an organic matrix. We preliminarily prepared and characterized Langmuir–Blodgett (LB) films of dipalmitoyilphosphatidic acid (DPPA), Self-Assembled (SA) monolayer of octadecylthiol (ODM) and Hybrid Films (HF) combining LB and SA technologies. l redox mediators were tentatively co-spread with DPPA molecules at the water–air interface and surface pressure-area (π–A) isotherms were recorded. On the basis of its evident tendency to remain incorporated into the monolayer, we select 3-3′,5-5′-tetramethylbenzidine (TMB) and we prepared LB and HF films containing TMB on different solid supports. The resulting structures were characterized by means of ellipsometry and contact angle measurements as a function of mediator content. ochemical characterization was performed on the same systems, recording cyclic voltammograms as a function of the number of layers constituting the film at two different transfer surface pressures (πtr). ms containing TMB were also characterized by means of UV–VIS spectroscopy, as a function of πtr and of the number of layers. o sets of independent results evidenced that TMB is quantitatively immobilized in LB nanostructures of DPPA maintaining its electroactive behaviour.