The length effect and color tuning of tetraphenylethylene functionalized oligothiophenes for effective detection of explosives.

Aggregation-induced fluorescent materials are of great importance in optoelectronics and bioelectronics in solid-state devices. Herein, functionalized oligothiophenes were designed and synthesized with the tetraphenylethylene (TPE) groups to explore the length effect and color tuning for the effective detection of explosives. Remarkably, compounds 2TPE1T and 2TPE2T show an aggregation-induced emission phenomenon, while longer π –conjugated molecules 2TPE3T , 2TPE4T , TPE5T and 2TPE6T show aggregation-caused quenching character, where the reason has been explained based on UV – Vis spectra ranging from 378 to 446 nm. Furthermore, fluorescent titration experiments demonstrate that dye 2TPE1T has a better response than dye 2TPE2T for nitroaromatics. The visual detection limit of 2,6-DNT is 18.2 ng/cm2 in the test strip of 2TPE1T. In addition, there is an exquisitely linear curve between the theoretical and experimental energy levels for TPE functionalized oligothiophenes. The influence of introducing TPE end-capped on the energy gap convergence has also been discussed, showing the energy level correlation of linear fitting combined with a theoretical and experimental perspective. This result not only paves the way toward π –functional materials but also expands their applications. [Display omitted] • A family of TPE functionalized oligothiophenes has been prepared. • Dyes 2TPE1T and 2TPE2T show an AIE phenomenon. • Dye 2TPE1T has a better response than dye 2TPE2T for nitroaromatics. • Naked-eye detection limit of 2,6-DNT is 18.2 ng/cm2 in the test strip of 2TPE1T. • An exquisitely linear curve is observed between theoretical and experimental. [ABSTRACT FROM AUTHOR]