A multifunctional fluorescent probe based on Schiff base with AIE and ESIPT characteristics for effective detections of Pb2+, Ag+ and Fe3

Jianing Zhao; Ciqin Li; Sihan Wei; Chengwei Lü; Li-Wei Zou

doi:10.1016/j.saa.2023.122904

A multifunctional fluorescent probe based on Schiff base with AIE and ESIPT characteristics for effective detections of Pb²⁺, Ag⁺ and Fe³

Spectrochim Acta A Mol Biomol Spectrosc. 2023 Nov 5:300:122904. doi: 10.1016/j.saa.2023.122904. Epub 2023 May 21.

Authors

Jianing Zhao¹, Ciqin Li², Sihan Wei¹, Chengwei Lü³, Li-Wei Zou⁴

Affiliations

¹ College of Chemistry and Chemical Engineering, Liaoning Normal University, Huanghe Road 850#, Dalian 116029, PR China.
² Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, PR China.
³ College of Chemistry and Chemical Engineering, Liaoning Normal University, Huanghe Road 850#, Dalian 116029, PR China. Electronic address: chengweilv@126.com.
⁴ Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, PR China. Electronic address: chemzlw@163.com.

PMID: 37229941
DOI: 10.1016/j.saa.2023.122904

Abstract

In this work, three Schiff-based fluorescent probes with aggregation-induced emission (AIE) and excited intramolecular proton transfer (ESIPT) characters were synthesized by grafting 2-aminobenzothiazole group onto 4-substituted salicylaldehydes. More important, a rare tri-responsive fluorescent probe (SN-Cl) was developed by purposeful variation of substituents in the molecule. It could selectively identify Pb²⁺, Ag⁺ and Fe³⁺ in different solvent systems or with the help of masking agent and show complete fluorescence enhancement without interference of other ions. Meanwhile, the other two probes (SN-ON and SN-N) could only recognize Pb²⁺ in DMSO/Tris-HCl buffer (3: 7, v/v, pH = 7.4). According to Job's plot, density functional theory (DFT) calculations and NMR analysis, coordination between SN-Cl and Pb²⁺/Ag⁺/Fe³⁺ was determined. The LOD values for three ions were as low as 0.059 μM, 0.012 μM and 8.92 μM, respectively. Ideally, SN-Cl showed satisfactory performance in real water samples detection and test paper experiments for three ions. Also, SN-Cl could be used as an excellent imaging agent for Fe³⁺ in HeLa cells. Therefore, SN-Cl has the ability to be a "single fluorescent probe for three targets".

Keywords: AIE; ESIPT; Metal ions detection; Multifunctional fluorescent probe; Schiff base.