Muscle tissue performs crucial contraction/extension motions that generate mechanical force and work by consuming chemical energy. Inspired by this naturally created biomolecular machine, artificial molecular muscles are designed and synthesized to undertake linear actuation functions. However, most of these muscle-like actuators are performed at large ensembles, while to realize the nanoscale actuation at the single- to few-molecule level remains challenging. Herein, we developed an artificial muscle-like molecular actuator that can reversibly control the proximity of the attached nano-objects, gold nanoparticles, within the single-molecule length level by its stimuli-responsive muscle-like linear contraction/extension motion. The molecular actuation motion is accompanied by an optical signal output resulting from the plasmonic resonance properties of gold nanoparticles. Meanwhile, the thermal noise of the muscle-like molecular actuator can be overcome by integrating the optical signal over a sufficiently long period.

肌肉组织执行关键的收缩/伸展运动，这些运动通过消耗化学能来产生机械力并起作用。受到这种自然创造的生物分子机器的启发，人工分子肌肉被设计和合成以承担线性驱动功能。然而，大多数这些类似肌肉的致动器是在大型集合体中执行的，而要实现单分子至少数分子水平的纳米级致动器仍然具有挑战性。本文中，我们开发了一种人工肌肉样分子致动器，通过其刺激响应性肌肉样线性收缩/伸展运动，可以在单分子长度水平内可逆地控制附着的纳米物体金纳米颗粒的接近度。分子致动运动伴随着由金纳米颗粒的等离子体共振特性产生的光信号输出。同时，可以通过在足够长的时间段上积分光信号来克服肌肉样分子致动器的热噪声。