Biofuel-driven Adaptable n-type Supramolecular Wires: Mimicking Conducting Microbial Nano-filaments
We report the biofuel-driven self-assembly of a benzimidazole-pyridine platinum (II) complex into supramolecular nanowires. Phosphate promotes Pt{middle dot}{middle dot}{middle dot}Pt metallophilic stacking, whereas the pristine complex forms nanosheets dominated by {pi}-{pi} interactions. By varying phosphate denticity (adenosine/guanosine mono-, di-, and triphosphates), we tune the extent of Pt{middle dot}{middle dot}{middle dot}Pt interactions and the resulting electrical conductance of the nanowires, measured on graphene using a custom EGaIn setup. Triphosphate-templated nanowires exhibit nearly four orders of magnitude higher conductance than non-templated nanosheets. Thermopower measurements reveal a negative Seebeck coefficient, indicating LUMO-mediated electron transport and rare n-type behavior in these supramolecular assemblies. Temperature-dependent measurements show a transition from tunneling (non-templated nanosheets) to thermally activated hopping (triphosphate templated nanowires). The system is recyclable, apyrase hydrolysis disrupts the nanowires, and re-addition of phosphate restores assembly, enabling reversible conductance switching over multiple cycles. This study demonstrates a fuel-responsive, adaptive supramolecular electronic material, highlighting how controlled Pt{middle dot}{middle dot}{middle dot}Pt interactions can be exploited to program charge transport in soft, bioinspired electronic systems.