On the distinct molecular architectures of dipping- and spray-LbL films containing lipid vesicles

Abstract

The introduction of spraying procedures to fabricate layer-by-layer (LbL)films has brought newpossibilities for the control of molecular architectures and for making the LbL technique compliant with industrial processes. In this study we show that significantly distinct architectures are produced for dipping and spray-LbL films of the same components, which included DODAB/DPPG vesicles. The films differed notably in their thickness and stratified nature. The electrical response of the two types offilms to aqueous solutions containing erythrosinwas also different.With multidimensional projectionswe showed that the impedance for theDODAB/DPPG spray-LbL film ismore sensitive to changes in concentration, being thereforemore promising as sensing units. Furthermore, with surface-enhanced Raman scattering (SERS) we could ascribe the high sensitivity of the LbL films to adsorption of erythrosin.