Design and synthesis of phenothiazine-based D-A molecules with ICT characteristics as efficient fluorescent probes for detecting hypochlorite in water

Jing Xu; Qinye Tian; Qirui Chu; Yu Zhang; Mengqi Zou; Hongbo Zhao; Ying Liu; Wenyi Chu

doi:10.1016/j.saa.2024.125491

Design and synthesis of phenothiazine-based D-A molecules with ICT characteristics as efficient fluorescent probes for detecting hypochlorite in water

Spectrochim Acta A Mol Biomol Spectrosc. 2024 Nov 26:328:125491. doi: 10.1016/j.saa.2024.125491. Online ahead of print.

Authors

Jing Xu¹, Qinye Tian¹, Qirui Chu², Yu Zhang¹, Mengqi Zou¹, Hongbo Zhao¹, Ying Liu³, Wenyi Chu⁴

Affiliations

¹ School of Chemistry and Materials Science, Heilongjiang University, Harbin 150080, PR China.
² School of Hydraulic and Electric Power, Heilongjiang University, Harbin 150080, PR China.
³ School of Hydraulic and Electric Power, Heilongjiang University, Harbin 150080, PR China. Electronic address: liuyingzjb@163.com.
⁴ School of Chemistry and Materials Science, Heilongjiang University, Harbin 150080, PR China. Electronic address: wenyichu@hlju.edu.cn.

PMID: 39615094
DOI: 10.1016/j.saa.2024.125491

Abstract

Phenylthiazide compounds are frequently utilized to construct electron donor-acceptor (D-A) dyes, exhibiting excellent fluorescence and colorimetric analysis performance due to their electron-rich properties. Three D-A type compounds 5a-c, featuring intramolecular charge transfer (ICT) characteristics, were designed and synthesized using phenothiazine as the donor and various aryl-substituted imidazoles as acceptors for the detection of hypochlorite. Additionally, the ICT properties of the compounds can be fine-tuned by introducing various substituents to achieve a more sensitive optical response to HClO/ClO^-. Among these, compound 5c, which contains the electron-withdrawing group -CN, demonstrated high sensitivity (3.5 nM), high selectivity, and a rapid response to HClO/ClO^-. Experimental results indicated that the strategy based on structural tuning presents a promising approach for optimizing fluorescent probes. To broaden practical applications, compound 5c was fabricated into paper test strips and thin-layer chromatography (TLC) plates for on-site analysis and detection of HClO/ClO^-. The compound was capable of detecting HClO/ClO^- not only in actual water samples but also in complex environmental water samples, thereby providing a convenient tool for real-time HClO/ClO^- detection.

Keywords: Complex water samples; Hypochlorite; Imidazole; On-site analysis; Phenothiazine.