Filip J R Meysman, Bent Smets, Silvia Hidalgo-Martinez, Nathalie Claes, Bob C Schroeder, Jeanine S Geelhoed, Yun Liu, Jiji Alingapoyil Choyikutty, Tamazouzt Chennit, Thijs Bodson, Alberto Collauto, Maxie M Roessler, Dmitry Karpov, Sylvain Bohic, Matteo Aramini, Shusaku Hayama, Maxwell Wetherington, Martijn A Zwijnenburg, Galina Pankratova, Isabel Pintelon, Jean-Pierre Timmermans, Gert Nuyts, Karolien De Wael, Sara Bals, Jo Verbeeck, Han Remaut, Henricus T S Boschker
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.