Chen Yi-Fan, Pruthi Vaishali, Lee Lin-Ruei, Liu Yu-Chun, Chang Ming-Hsuan, Théato Patrick, Chen Jiun-Tai
Department of Applied Chemistry, National Yang Ming Chiao Tung University, 300093 Hsinchu, Taiwan.
Institute for Chemical Technology and Polymer Chemistry (ITCP), Karlsruhe Institute of Technology (KIT), Kaiserstraße 12, D-76131 Karlsruhe, Germany.
ACS Nano. 2024 Oct 1;18(39):26948-26960. doi: 10.1021/acsnano.4c08801. Epub 2024 Sep 20.
Artificial photomodulated channels represent a significant advancement toward practical photogated systems because of their remote noncontact stimulation. Ion transport behaviors in artificial photomodulated channels, however, still require further investigation, especially in multiple nanochannels that closely resemble biological structures. Herein, we present the design and development of photoswitchable ion nanochannels inspired by natural channelrhodopsins (ChRs), utilizing photoresponsive polymers grafted anodic aluminum oxide (AAO) membranes. Our approach integrates spiropyran (SP) as photoresponsive molecules into nanochannels through surface-initiated atom transfer radical polymerization (SI-ATRP), creating a responsive system that modulates ionic conductivity and hydrophilicity in response to light stimuli. A key design feature is the reversible ring-opening photoisomerization of spiropyran groups under UV irradiation. This transformation, observable at the molecular level and macroscopically, allows the surface inside the nanochannels to switch between hydrophobic and hydrophilic states, thus efficiently modulating ion transport via changing water wetting behaviors. The patternable and erasable polySP-grafted AAO, based on a controllable and reversible photochromic effect, also shows potential applications in anticounterfeiting. This study pioneers achieving macroscopic anticounterfeiting and photoinduced photoswitching through reversible surface chemistry and expands the application of polymer-grafted structures in multiple nanochannels.
人工光调制通道因其远程非接触刺激特性，代表了实用光控系统的一项重大进展。然而，人工光调制通道中的离子传输行为仍需进一步研究，特别是在与生物结构极为相似的多个纳米通道中。在此，我们展示了受天然视紫红质通道（ChRs）启发的光开关离子纳米通道的设计与开发，利用接枝了光响应聚合物的阳极氧化铝（AAO）膜。我们的方法通过表面引发的原子转移自由基聚合（SI-ATRP）将螺吡喃（SP）作为光响应分子整合到纳米通道中，创建了一个响应系统，该系统可根据光刺激调节离子电导率和亲水性。一个关键的设计特点是螺吡喃基团在紫外光照射下的可逆开环光异构化。这种在分子水平和宏观层面均可观察到的转变，使纳米通道内部的表面能够在疏水和亲水状态之间切换，从而通过改变水的润湿行为有效地调节离子传输。基于可控且可逆的光致变色效应，可图案化且可擦除的聚SP接枝AAO在防伪方面也显示出潜在应用。本研究率先通过可逆表面化学实现宏观防伪和光诱导光开关，并扩展了聚合物接枝结构在多个纳米通道中的应用。
