The layer-by-layer assembly of polyelectrolyte functionalized graphene sheets: A potential tool for biosensing

In this paper, graphene surface was functionalized with polyacrylic acid (PAA) and was used as a building block to construct electrochemically functionalized multilayer via electrostatic layer-by-layer (LbL) assembly. Prussian Blue (PB) nanoparticles protected by poly(diallyldimethylammonium chloride) (PDDA–PB) were used as an example of electroactive species for the assembly. Through electrostatic interaction, the modified-graphene (PAA–graphene) was assembled together with the positively charged PDDA–PB. Atomic force microscopy (AFM) was used to demonstrate the modification of graphene sheets and microstructure of the graphene-based multilayer. Furthermore, the multilayer (PAA–graphene/PDDA–PB)n film electrode was characterized with cyclic voltammetry for its potential use in biosensing. The electrode exhibited elctrocatalytic activity for the reduction of H2O2. It can be expected that this work will stimulate the development of efficient and advanced biosensing devices and the construction of new and potentially useful nanosystems.