Highly efficient long-range conduction through a biosynthetic nickel-organic framework

Biobased electronics aims for disruptive innovation in sustainable electronics but is obstructed by the low intrinsic conductivity of biomaterials. Recently, fibres were discovered within the cell envelope of multi-cellular cable bacteria, which display an exceptional conductivity for a biomaterial. Yet, the molecular structure and electron transport mechanism remain unresolved, thus precluding a detailed structure-function understanding and the development of biomimetic analogues. Here, we demonstrate that each fibre embeds an extended nickel-organic framework, which consists of a bundle of intertwined nanoribbons, each built from stacked repeat units in which multiple nickel centres are linked by organic dithiolene ligands. This metal-organic supramolecular architecture provides extensive conjugation and electron delocalization, thus enabling exceptional conductance over macroscale distances. This suggests a novel design principle for bio-based electronic materials and opens possibilities for biosynthesis of metal-organic frameworks.