Semi reflective biopolymer layers for the detection of biomass hydrolytic enzymatic activities

Structural colors were obtained by the deposition of plant cell walls biopolymers films on reflective support. Multilayered xyloglucan(XG)/cellulose nanocrystals(CN) thin films were obtained by spin-assisted layer-by-layer assembly while arabinoxylan (AX) thin films were elaborated via the spin-coating of AX/melamine formaldehyde resin followed by a cross-linking step. The effects of aqueous solutions on the stability of the structural colors were evaluated. The films were subsequently used to detect cellulase and xylanase activities by the change in the colors due to the film degradation. This enzymatic assay method appeared to be about 150 more sensitive that a standard method. Moreover due its simplicity, the method could be used to detect other biomass-hydrolyzing enzymes and more generally for other heterocatalytic degradations of solid polymer layers.