Department of Bioengineering, George Mason University, Fairfax, VA 22030, USA.
Department of Biomedical Engineering, University of Bridgeport, Bridgeport, CT 06604, USA.
Biomolecules. 2023 Jan 13;13(1):175. doi: 10.3390/biom13010175.
Carbon nanotubes (CNT) have fascinating applications in flexible electronics, biosensors, and energy storage devices, and are classified as metallic or semiconducting based on their chirality. Semiconducting CNTs have been teased as a new material for building blocks in electronic devices, owing to their band gap resembling silicon. However, CNTs must be sorted into metallic and semiconducting for such applications. Formerly, gel chromatography, ultracentrifugation, size exclusion chromatography, and phage display libraries were utilized for sorting CNTs. Nevertheless, these techniques are either expensive or have poor efficiency. In this study, we utilize a novel technique of using a library of nine tripeptides with glycine as a central residue to study the effect of flanking residues for large-scale separation of CNTs. Through molecular dynamics, we found that the tripeptide combinations with threonine as one of the flanking residues have a high affinity for metallic CNTs, whereas those with flanking residues having uncharged and negatively charged polar groups show selectivity towards semiconducting CNTs. Furthermore, the role of interfacial water molecules and the ability of the tripeptides to form hydrogen bonds play a crucial role in sorting the CNTs. It is envisaged that CNTs can be sorted based on their chirality-selective interaction affinity to tripeptides.
碳纳米管（CNT）在柔性电子、生物传感器和储能设备方面具有引人入胜的应用，根据其手性可分为金属性或半导体性。由于其能带隙类似于硅，半导体 CNT 被视为电子器件中构建块的新材料。然而，为了实现这些应用，必须将 CNT 分类为金属性和半导体性。以前，凝胶色谱法、超速离心法、尺寸排阻色谱法和噬菌体展示文库被用于 CNT 的分类。然而，这些技术要么昂贵，要么效率低下。在这项研究中，我们利用一种使用含有甘氨酸作为中心残基的九种三肽文库的新技术，研究侧链残基对 CNT 大规模分离的影响。通过分子动力学，我们发现，具有苏氨酸作为侧链残基之一的三肽组合对金属 CNT 具有高亲和力，而具有非带电和带负电极性侧链残基的三肽组合对半导体 CNT 具有选择性。此外，界面水分子的作用以及三肽形成氢键的能力在 CNT 的分类中起着至关重要的作用。可以预见的是，CNT 可以根据其手性选择性相互作用亲和力来进行分类。
