Enzymatic tandem systems engineered from mesoporous thin films: Synergy leading to efficient starch-electricity conversion

Abstract

The synergetic combination of nanomaterials with biomolecules, which is inherent to natural systems is a challenging and thriving field. In Nature, a wide variety of enzymes work together in multi-step reactions into sophisticated subcellular compartments. Mesoporous Oxide Thin Films (MOTF) permit to divide the space in highly ordered functional domains, providing a promising multiscale scaffold to host enzymes. However, the emergent properties of MOTF in which enzymes are hierarchically ordered and coupled together have not been explored yet. Here, we demonstrate how the confined cavities of an organized multilayer of MOTF, in resemblance to living cell compartments, can be used to host two different enzymes to activate a cascade of enzyme reactions that do not proceed under free enzyme conditions. Transformation of complex carbohydrates such as starch to electricity is widely recognized to be an important technological objective. The MOTF multilayer was used as a bionanofactory, achieving a starch-fuelled biofuel cell that yields the best performance obtained so far, jointly with reduced operating fuel requirement. This development demonstrates that enzymatic pathways can be engineered from mesoporous thin film architectures, opening the way for evolving bio-active surfaces in packaging, sensors, prosthetics, or bioMEMS among other exciting applications.