A new perylene-based fluorescent pH chemosensor for strongly acidic condition

Fei Ye; Xiao-Min Liang; Nan Wu; Ping Li; Qiong Chai; Ying Fu

doi:10.1016/j.saa.2019.03.049

A new perylene-based fluorescent pH chemosensor for strongly acidic condition

Spectrochim Acta A Mol Biomol Spectrosc. 2019 Jun 5:216:359-364. doi: 10.1016/j.saa.2019.03.049. Epub 2019 Mar 19.

Authors

Fei Ye¹, Xiao-Min Liang¹, Nan Wu¹, Ping Li¹, Qiong Chai¹, Ying Fu²

Affiliations

¹ Department of Applied Chemistry, College of Science, Northeast Agricultural University, Harbin 150030, PR China.
² Department of Applied Chemistry, College of Science, Northeast Agricultural University, Harbin 150030, PR China. Electronic address: fuying@neau.edu.cn.

PMID: 30921658
DOI: 10.1016/j.saa.2019.03.049

Abstract

A highly selective and sensitive pH chemosensor N,N-bis[(2-thiophene)-ethyl]-3,4,9,10-perylene tetracarboxylic diimide (TEPTD) was designed and synthesized through Schiff-base condensation reaction. It exhibited large Stokes shifts, good water solubility, excellent selectivity and outstanding photo-stability. The pK_a of the probe was 3.0, which indicated that it could be used in highly acid conditions. With the addition of H⁺, the fluorescence intensity increased gradually. The sensing mechanisms involved photo-induced electron transfer, protonation and deprotonation, which were confirmed by ¹H NMR titration experiment with trifluoroacetic acid. The probe can be used as a convenient probe to distinguish acidic from neutral or alkaline solutions by "naked-eye".

Keywords: PET; Perylened derivatives; Protonation; Schiff base; pH Chemosensor.