First fluorescent sensor for lutein in aqueous media based on thiosemicarbazide‐bridged bis‐tetraphenylethylene

Abstract

This work designed and synthesized the first organic fluorescent sensor for lutein in aqueous solutions based on blue to yellow fluorescence change of thiosemicarbazide‐bridged bis‐tetraphenylene (Bis‐TPE). By condensing monohydroxy tetraphenylene derivatives with p‐phenylene di‐isothiocyanate, Bis‐TPE was produced. A fluorescence spectrophotometer was used to scan the fluorescence emission spectra from 380 to 700 nm with 360 nm as the excitation wavelength. The fluorescence spectra showed that Bis‐TPE exhibited high selective sensing ability for lutein in aqueous medium, and the fluorescence showed red‐shift phenomenon with a limit of detection as low as 0.26 μM for lutein. The sensing mechanism was confirmed by mass spectrometry, infrared, and fluorescence Job's plots based on the 1:1 stoichiometric ratio of double hydrogen bonding. The successful application of Bis‐TPE in sensing test strips means that Bis‐TPE can achieve efficient detection of lutein in complex environments. As a result, an aggregation‐induced luminescence‐based lutein fluorescence sensor was constructed, which exhibited highly selective and sensitive sensing of lutein, and provided a new research idea for the object detection of such structures.