Multi-State Resistance in Microtubule-Templated Gold Nanowires.

The scaling limitations of conventional transistors demand alternative device concepts capable of dynamic reconfigurability at the atomic scale. Resistive switching, a key mechanism for neuromorphic computing and non-volatile memory, has been widely demonstrated in oxides, semiconductors, and nanocomposites, but not in pure one-dimensional metallic systems. Here, we report the first electrical characterization of gold nanowires (AuNWs) synthesized within the lumen of functionalized microtubules. Structural analyses confirm continuous metallic AuNWs with local compositional inhomogeneities. Electrical measurements reveal three distinct conduction behaviors and abrupt resistance transitions under applied bias, consistent with electromigration driven by structural reorganization. Millisecond voltage pulsing enables active and reproducible modulation of resistance states without loss of metallic conduction, establishing a possible new multi-state RS mechanism intrinsic to pure metallic nanowires. Owing to their high aspect ratio, lateral geometry, and CMOS-compatible processing, microtubule-templated AuNWs provide a versatile platform for reconfigurable interconnects.