科研之友
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摘要
Ion channels that exist in the living systems play important roles in maintaining normal physiological processes, and they have attracted great attentions of scientists because of their unique property in many biological activities. Learning from nature become an important source of new materials development. Inspired by natural biological ion channels, artificial polyethylene terephthalate (PET) nanochannel was built by track-etched method and served as one kind of the biomimetic ion channels in this paper. By introducing the idea of asymmetric modification in the PET cylindrical nanochannels, we designed and fabricated an artificial nanochannel system with high and controllable rectification, which ion transport properties can be regulated by Au nanoparticles. PET cylindrical nanochannels are modified with 2-undecyl-1-disulfide ureidoethyl quaternary imidazolinium salt (SUDEI) by electrostatic adsorption, resulting in positively charged on one side of PET cylindrical nanochannels. Since the other side of nanochannels are negatively charged, this membrane exhibits rectified properties with asymmetric charge distribution and geometric structure. The movement of cation presents a priority direction, which is from SUDEI side to the other side, and the opposite direction is suppressed. The ion transportation properties of the nanochannels can be investigated by measuring the current-voltage characteristics, and the diode-like behavior is quantified by the current rectification ratios. By introducing the SUDEI, PET nanochannels have a non-linear ion transport properties, showing better gating performance. In addition, the rectification ratios of this system can be regulated by SUDEI modification time and Au nanoparticles. SUDEI contains active sulfur element, resulting in Au nanoparticles stably bounding to SUDEI with Au-S bond. Therefore, the addition of Au nanoparticles can further increase the nanogating ratio because it can reduce the effective diameter of the cylindrical nanochannels, making the system more asymmetrical. And the ion transport in this system exhibits excellent stability. This system provides a new design idea for further research on more complicated functionalization and smart nanochannel systems.
- 出版日期2016
- 单位北京航空航天大学
