Tetraphenylethylene-Substituted Bis(thienyl)imidazole (DTITPE), An Efficient Molecular Sensor for the Detection and Quantification of Fluoride Ions

Ranjith Kumar Jakku,Govind Reddy,Giribabu Lingamallu,Steven H Privér,Anil Kumar Vardhaman,Suresh Kumar Bhargava,Nedaossadat Mirzadeh,Rajiv Trivedi

doi:10.3390/chemosensors9100285

Abstract

Fluoride ion plays a pivotal role in a range of biological and chemical applications however excessive exposure can cause severe kidney and gastric problems. A simple and selective molecular sensor, 4,5-di(thien-2-yl)-2-(4-(1,2,2-triphenylvinyl)-phenyl)-1H-imidazole, DTITPE, has been synthesized for the detection of fluoride ions, with detection limits of 1.37 × 10−7 M and 2.67 × 10−13 M, determined by UV-vis. and fluorescence spectroscopy, respectively. The variation in the optical properties of the molecular sensor in the presence of fluoride ions was explained by an intermolecular charge transfer (ICT) process between the bis(thienyl) and tetraphenylethylene (TPE) moieties upon the formation of a N-H---F− hydrogen bond of the imidazole proton. The sensing mechanism exhibited by DTITPE for fluoride ions was confirmed by 1H NMR spectroscopic studies and density functional theory (DFT) calculations. Test strips coated with the molecular sensor can detect fluoride ions in THF, undergoing a color change from white to yellow, which can be observed with the naked eye, showcasing their potential real-world application.

Highlights

The detection and recognition of anionic analytes has developed into an extremely active research field in recent years [1,2,3,4,5,6,7,8,9,10,11,12,13,14]
Fluoride ions play a significant role in dental health [18] and has been utilized for the treatment of osteoporosis [19,20,21] and for military uses, including the refinement of uranium for nuclear weapons [22]
Tetrahydrofuran was used for the sensing experiments, which was freshly dried optimized the density functional theory (DFT)/Becke, 3-parameter, lee–yang–parr(B3LYP)/6-31+G(d,p)

Summary

Introduction

The detection and recognition of anionic analytes has developed into an extremely active research field in recent years [1,2,3,4,5,6,7,8,9,10,11,12,13,14]. Anions play a crucial role in a range of biological and chemical processes, and their detection, even at extremely low concentrations, has been the motivation for continuous improvement in sensor development over the last few decades [15,16]. Fluoride ions play a significant role in dental health [18] and has been utilized for the treatment of osteoporosis [19,20,21] and for military uses, including the refinement of uranium for nuclear weapons [22]. It is readily absorbed by the human body

Methods

Results

Conclusion