Detection of volatile organic compounds, water in organic solvents, and anions using all-in-one type fluorescent emitters, and their data protection applications

Abstract

Multifunctional emitters with excellent fluorescence are highly desirable. Herein, two triphenylamine-based emitters, TPA-SYQ and TPA-BQ with D–π–A structures and showing obvious solvent polarity-sensitive fluorescence in different organic solvents, are presented. Upon increasing the solvent polarity, they exhibited strong bright blue to weak yellow-orange fluorescence along with large Stokes shifts up to approximately 205 nm. The fluorescence features were quantitatively studied from the relationship between the solvent E_T(30)s and the Stokes shifts, and were attributed to the charge transfer excited states. The fluorescence was easily influenced by different polar solvent molecules, and thus, to induce emission shifts, they were interpreted by theoretical calculations including molecular orbitals and natural transition orbitals. Considering the unique solvent polarity-sensitive fluorescence and the ability to detect VOCs and the water content in organic solvents, encryption and anti-counterfeiting were developed. In addition, TPA-SYQ showed a strong green fluorescence response to the F⁻ ion compared to other anions. The detection limit of 5.1 × 10⁻⁷ M was determined, as well as anti-interference ability, stoichiometry, and deprotonation sensing mechanism, and F⁻ ion practical detection was fully carried out. All-in-one type organic emitters realizing three detection tasks and two data security applications were created that integrate multi-tasks onto one emitter and provide a reference for developing high-performance and multifunctional organic emitters.