Aggregation-Driven Fluorescence: Decoding Cooperative Artificial Motors Enable Bimodal Emission in Semi-Solid Biohybrid Systems.

Abstract

Understanding the cooperative working principle of artificial rotary motors is essential for developing complex biohybrid systems. Such systems could enable critical tasks like proton and ion transport through artificial membranes or gating in artificial valves. To investigate cooperative transitions, we studied our double ratchet motor (DRM), composed of a Brownian rotor and a power stroke rotor, both coupled to a shared stator (-C≡C-). While DRMs exhibit stable rotary motion in compatible solvents, their integration into adaptive bio-synthetic systems remains challenging. We explored DRM behavior in a semi-solid chitosan matrix, revealing thermally activated metastable rotational states. The accumulation of these states led to aggregation-induced fluorescence emission, displaying both high-energy blue shifts and red shifts. We fabricated DRM-embedded chitosan hybrid films to investigate this bimodal emission, attributing DRM aggregation to binary solvent-induced clustering. These findings provide insight into the molecular mechanisms underpinning motor-driven fluorescence modulation. This study advances the potential of artificial motors in biohybrid materials, paving the way for their integration into biochemical reaction networks and adaptive synthetic systems.