Highly responsive triethylamine vapor sensor based on a perylene diimide-polydiacetylene system via heat-induced tuning of the molecular packing approach

Abstract

Triethylamine (TEA) is a kind of volatile organic compound (VOC) and the most preferred organic amine as a reagent, catalyst, and organic solvent in industrial production. However, in addition to its pungency odorous characteristic, TEA can have deleterious short-term and long-term effects on human health and the environment. Therefore, it is important to design and develop a highly sensitive and selective TEA sensor that allows for fast and timely detection. Herein, we report a highly sensitive TEA sensor based on perylene diimide-polydiacetylene (PDI-PDA2) nanofibers. A strategy of UV-induced polymerization under continuous heating (to 130 °C) was adopted to trap and preserve the molecular orientation of the post-crystal-crystal phase transition by virtue of a robust PDA backbone. Analyzing the molecular–packing–performance relationship revealed a dramatic enhancement of TEA vapor detection response due to crystal-crystal transition in PDI-PDA solid. The lower LUMO energy level for PDI-PDA2 is proved to enhance the sensing performance by enabling efficient charge mobility between PDI and TEA. We believe that this study will encourage further research to design improved VOC sensing devices based on the molecular–packing arrangement.