A Simple Perceptive Diphenyl‐Imidazole‐Based Dipodal Schiff‐Base Chemosensor for Zn²⁺ and PPi ions and Its Live‐Cell Imaging Applications

Abstract

2,6-bis((E)- (2-(benzo[d]thiazol-2-yl)hydrazono)methyl)-4-(4,5-diphenyl-1H-imidazol-2-yl)phenol (PIS) conjugate has been designed as a selective fluorescent probe for zinc ion. The PIS exhibits selectivity towards Zn 2 + among various ions in DMSO-H 2 O (1:9) v/v 50 mM HEPES (4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid) at pH = 7.4. Moreover, the detection of PIS towards Zn 2 + ion could be realized in " naked eye" with a color conversion from yellow to greenish yellow. The linear relationship between fluorescence intensity and Zn 2 + ion concentration indicates that PIS can be used for quantification of Zn 2 + ion. The PIS probe can be used in broad pH ranging from 4 to 9. The limit of detection (LOD) was found to be 0.52 nM for Zn 2 + ion. The binding ratio and binding constant of PIS-Zn 2 + complex were determined and calculated as 1:1 and 2.36 × 10 6 M À 1 according to Job's plot and Benesi-Hildebrand equation, respectively. Furthermore, the PIS-Zn 2 + complex subsequently acted as a secondary fluorescent turn-off probe for pyrophosphate (PPi) ion recognition among the other anions. To assess the real-world efficacy of the PIS and PIS-Zn 2 + complex, they were evaluated by test paper strips. Likewise, the probe PIS and PIS-Zn 2 + complex were used as in vitro cell imaging probe, and successfully demonstrated as feasible biomarker as well.

Performance of 4,5‐diphenyl‐1H‐imidazole derived highly selective ‘Turn‐Off’ fluorescent chemosensor for iron(III) ions detection and biological applications

“…In our ongoing research, the utilization of imidazole compounds for metal sensing represents a distinctive aspect of our work [10]. Researchers have predominantly concentrated on developing fluorescent and colorimetric chemosensors over alternative methods for detecting metal ions due to their superior selectivity, high sensitivity, ease of use, and cost‐effectiveness.…”

“…In our ongoing research, the utilization of imidazole compounds for metal sensing represents a distinctive aspect of our work [10].…”

Selective fluorescent detection of Zn2+ by a rhodanine‐based chemosensor

“…many of these probes have poor water solubility and limited practical application in the environment. [36][37][38][39] On the other hand, the rhodanine derivatives have been recently applied in fluorescent sensing and pharmacological fields due to their diverse properties, which are antiviral, water-soluble, and antimicrobial. [40][41][42] Moreover, they have three electrondonating heteroatoms (S, N, and O), which can easily interact with metal ions.…”

A Selective and Reversible Fluorescent Probe for Zn2+ Detection in Living Cells

“…Over the past decade, a numbe of fluorescent probes for Zn 2+ detection based on different fluorophore derivatives have been reported, such as rhodamine, fluorescein, coumarin, naphthalimide, pyrene, BODIPY, Schiff base derivatives, tetraphenylethylene, and other fluorophores, involving different mechanisms including PET (photoinduced electron transfer), ESIPT (intramolecular proton transfer), AIE (aggregation‐induced emission), ICT (intramolecular charge transfer), etc. These probes have strong binding ability with Zn 2+ , and some of them can also be used for biological imaging.…”

“…Currently, the fluorescent methods using small molecule probes are excellent means of detecting zinc ions in aqueous solutions and live cells because of high sensitivity and selectivity, low detection limit, fast response, operational simplicity and real-time monitoring. [23][24][25][26][27] Over the past decade, a numbe of fluorescent probes for Zn 2 + detection based on different fluorophore derivatives have been reported, such as rhodamine, [28,29] fluorescein, [30,31] coumarin, [32,33] naphthalimide, [34][35][36] pyrene, [36][37][38] BODIPY, [39] Schiff base derivatives, [38,40,41] tetraphenylethylene, [34,42] and other fluorophores, [43][44][45] involving different mechanisms including PET (photoinduced electron transfer), ESIPT (intramolecular proton transfer), AIE (aggregation-induced emission), ICT (intramolecular charge transfer), etc. These probes have strong binding ability with Zn 2 + , and some of them can also be used for biological imaging.…”