Nanofilm coatings for transport control and biocompatibility

Ultrathin nanofilm coatings are proposed as novel dual-purpose materials for sensor applications. Flux-based biosensors, such as those employing enzymes, require incorporation of a diffusion-limiting coating to balance the incoming substrates with reaction kinetics to obtain a measurable signal. Furthermore, if the sensors will be used in vivo, the outer surface must be biocompatible, which requires resistance to adsorption of proteins. An attractive solution for controlling diffusion and blocking nonspecific adsorption is the layer-by-layer (LbL) self-assembly method, which allows for the construction of nanocomposite ultrathin films comprising multiple layers of polymers with alternating charge. This paper describes the construction and characterization of nanofilms with different compositions to assess their biocompatibility and permeability to model analytes such as glucose and urea.